ATI Catalyst Control Center (CCC) won’t start

If you have an ATI Video card and use the Catalyst Control Center program and you have the problem that CCC won’t start, here’s the solution.

My solution was to clear out the  Windows GAC (Global Assembly Cache).  In Windows 7, you can browse  directly to “C:Windowsassembly”.  Sort by “Public Key Token”, then  delete everything with the Token “90ba9c70f846762e” (ATI’s key).  You’ll  obviously need Administrator privileges.  No reboot needed either.   Reinstalled CCC and it ran perfectly!


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  1. Thanks for the tip, CCC just stopped launching for me for some reason… tried everything including reinstalling all drivers and cleaning drivers etc before but nothing worked.

    I’m actually on XP pro, but deleting the assembly cache and reinstalling only CCC worked perfectly.

  2. thank you. I’ve been fighting this issue for two days. Your fixed, worked!!

  3. Claude says:


    could it be possible that win 7pro is diffrent cant find the file tons of keys but none with 90 or ati refrence, I have admin and no problem uninstall but cant find this file you speak of. The ccc host will not start and cant get it resolve had a nvidia card made sure it was completely out of the system . But the ccc on the 5870 will not work .I have direct x 11 it is what the card is rated for . i removed the driver and program reboot still wont start seems i should be able to fix this without formating.Thanks for any help or suggestions you may have .Also it is the latest driver and ccc tried older one still would not work.

  4. Yesterday, following on a Phoenix BIOS upgrade on my fancy new Chronos 7 Samsung laptop, suddenly I had this problem. Oh noes. I fixed the error in ten very simple steps. Hopefully they’ll work for you, too. A little bit nerve wracking to be sure – as fiddling around with anything related to core components always is – but really this fix is basically just an off/on toggle so, nothing ventured, nothing gained. You certainly can’t break anything by trying it.

    1. Open Windows Explorer
    2. Go to the c:\ directory and right click directly on Users sub directory.
    3. Select Properties.
    4. Under the General tab place a check in the box for “Hidden” attributes.
    5. Hit Apply and check “Yes” to have your selection apply to all the Users sub directories.
    6. Wait while all the files get toggled. This will make all the Users Directory files disappear from Explorer’s right pane when the operation is finished – but don’t be alarmed, the Users Directory itself will still be present in the Explorer’s left pane.
    7. Right Click the Users Directory again.
    8. Choose Properties
    9. Under the General tab, remove the check mark for Hidden attributes again.
    10. Once this operation is completed all the files in your Users directory will re-appear in the right hand pane, Catalyst Control Center should function normally again and all should be right with your world.

    (I don’t think this fix should be Op system dependent so it probably works on Vista and XP too, but I can’t say that with total certainty, having not tried it. One of the ongoing mysteries about operating systems, imo, is why pgms sometimes forget if their default position is on or off. Many people were plagued with that dilemma with Sound in win xp, continually having to go into system properties to check/uncheck then recheck the switch again in order for audio to work. Hopefully that’s not the case with the Catalyst Control Center – but after using this fix I’ve rebooted my laptop half a dozen times and the Control Center still works. )

    • Should have mentioned in the Users hidden off/on solution that, of course, you will need to have administration privileges to carry out the procedure.

  5. Vegard Hansen says:

    ”access is denied (all the filenames in a list)” everything uninstalled, and i am admin… what now?

    thank you for helping!

  6. You, sir, are my savior.

    After almost a year of frustration I finally found a solution that works. Thank you so much!

  7. Wow… just wow! Thank you very much. I’m realy glad i came across this website. I was so looking for solution that would finally let me access CCC again.

    You are great.

    Kind regards

  8. Worked perfectly! Thank you so much.Had to use the shortcut to run as admin because I kept getting denied. Had 743 of those tokens.

  9. just wanted to chime in…this works for windows xp (i have sp3) as well.
    look in [local drive]:\WINDOWS\assembly and sort by public key token. delete all marked with ’90ba9c70f846762e,’ i had 191 files. CCC finally works!

  10. OMG OMG OMG! Thank you!!!!!! I’ve had this problem for over a year, and sunk a ton of wasted hours into this! Finally, a solution that worked. You’re my hero! :)

    By the way, I had the problem where, even as admin, it would not let me uninstall the files, but I was able to do so after following the suggestion to boot in safe mode. Just reboot and hold F8 down.

    Then everything worked like a champ!

    Thanks again!

  11. Geoffrey Ford says:

    Hey guys!! I have been working on this problem myself!!! None of this stuff above helped at all!
    What I did was uninstall all of your AMD/ATI software. Once this is down, proceed to go into your C:/Local disk/program files/. Once in here, delete your ATI, and also your ATI Technology folders. If you can’t delete the folders for some reason, just go into the folders and delete what you can. IN OTHER WORDS, TRY TO DELETE ALL OF ATI AND AMD STUFF OUT OF YOUR PROGRAM FILES. Then after this is done, go back to C:/Local disk/. Once in here just delete the file named AMD. If you can’t delete it for some reason, go in and delete what you can. Once this is done, go to where you have downloaded the ATI driver and double-click on it, so it starts to extract. Once extracted click cancel. Then go back into C:/Local disk/. Find AMD again but this time open it, then open up the folder called support. Once in here open up the version which was just extracted, then once it has opened, open up the folder called config. Once in here, find a file called InstallManager. Open this up in notepad, or wordpad either one it doesn’t matter. Once this is opened scroll down to the bottom and find the one where it says Workaroundinstall =false. Change this to true. Save it close the file, them re-install CCC.

    And presto!!! Once you have installed it and restarted your computer, your CCC will open!!!

    I hope this helps someone out there, because I know when I was searching I was on breaking point, not being able to find anything. :):):):):):):):)

    • i do what u told…..but when I want to open ccc, it showed “could not load file or assembly ‘mom.implementation or cli.implementation’ or one of its dependencies. the system cannot find the file specified”….what should I do?

    • Geoffrey,
      Thank you so much for this. I have spent hours trying to fix
      this and your solution worked!
      God Bless You!

  12. I just formatted my pc yesterday….yesterday after install CCC it open normally, today after install game, I want to change my graphic card setting..but it seem CCC won’t open….so frustated

  13. Hello,
    i am searching under “C:\Windows\assembly” and i see all the public key tokens… but none of them with the 90ba9c70f846762e

    however under “processor architecture” there are several that are tagged as “AMD64″. Is this what i am looking for??? i dont want to delete something and have to reformat my hardrive.

  14. Thank you so very much…. Had this problem for many days… You did it!

  15. Makenna says:

    Thank you so much for posting this! I have been looking for a resolution for the longest time and this worked like a charm.

  16. Thanks a thousand times.I had this problem for couple months,now I got it solved, thanks to you

  17. THIS WORKED! I can’t believe I can actually use CCC now! Thanks!

  18. Worked like charm!
    No restart, no re install CCC!
    Thank You!

  19. I have the same question as Colin and Mikkel:
    “I dont have said Public Token 90ba9c70f846762e in my Assembly. What now?” I don’t know how to find the version of CCC.

  20. You my friend are a life saver! I spent the last couple of days uninstalling and reinstalling and using drive sweeper and going into safe mood and losing my hair! This solved all my problems and I want to thank you very much!

  21. Thanks Much!

  22. thanks a lot.
    one funny thing happen. I logged as adm but when I delete the token, it display a error message saying to log with as adm, I check steps again, review other reply and whwn I look over again and it already delete the token!. Misterys of computer science

  23. Thanks for this! I actually didn’t have to reinstall the CCC, deleting those files/things was enough for the CCC to open up!
    Thank you so much!


  24. Marty Monahan says:


    Was having the problem that the ATI Catalyst Control Manager wouldnt start.

    Having just got a new bigger monitor, the overscan needed to be reset. After doing the above the ATICC fired up right away.

    Again thanks, I was on the verge of reinstalling windows to fix this.


  25. After a half a day of banging my head on my desk, this is what saved me. Thank you so much.

  26. THANKYOU SOOOOO MUCH!!!! Clearing out these ATI keys worked for me, CCC launched perfectly!! I’ve been fighting with this prob for days. THANKS AGAIN!!!!

  27. just like Mikkel on August 20, 2011 at 5:11 am, “I dont have said Public Token 90ba9c70f846762e in my Assembly. What now?” I don’t know how to find the version of CCC.

  28. Sounds good but where does one find a reliable site for the CCC reload? I’ve read about a C-Catalyst that is a malevolent program. Please let us know how to avoid that.

  29. i don’t have 90ba9c70f846762e either and im not sure what verison of ccc i have

  30. Awesome! Everything is working again. Your fix does the trick on Win XP installations too.
    Thanks a bunch!

    • Hey! Thanks for the help. Working through the safe mode let me fix it as you suggested. Worked like a charm.

      Thanks !!!!!

  31. Blacksnake9 says:

    Just wanted to say a big thank you! I have been trying to get CCC working for a week now and nothing worked. Finally I found this blog and BAM…. worked the first time. Nothing on ATI website even worked or helped. Thank You.

  32. I was getting permission denied also. A reboot into safe mode and I was able to remove them. Thanks for the good info.

  33. runawaywill says:

    I don’t have any files matching the keys.

  34. Oblivious says:

    This was great help! thnx. At first, it didnt allow me to delete the files but then went onto safe mode and did it. Eventually first of all unistalling all ATI stuff.

  35. Thanks, dude, you are awesome!!!!!

  36. Will this work if using Windows Vista 32-bit on a Dell Studio 1737 laptop? I tried to install new drivers through Dell earlier, which gave me an error message during installation, and wouldn’t open CCC even after exiting out. After a system restore I tried to reopen CCC but it still won’t open..

  37. i am unable to delete it. even following phillip’s way of making shortcut and running it as admin, it still has the same problem. saying Access is denied. any way to solve this?

  38. i haven’t got any tokens with 90ba9c70f846762e? my higest is 89? :(

  39. I had the same problem and I’m running windows vista 32 bit, Thank you so much! I’ve had this problem with CCC for more than a month lol. To everyone having trouble deleting the files, all you have to do is create a new shortcut with the path “%SystemRoot%explorer.exe C:Windowsassembly”. After that just right click the new shortcut and run as admin. Make sure after you delete the files to reinstall CCC obviously lol thanks again OP! :)

    I hade a lot of probs with My CCC not starting. Tried all kindas of Sh** to fix it.
    Nothing worked….Untill Now…thx to this guide :-)


  41. I am having the same issue as Junkrider and Sivert had, getting access denied when i try delete, i am administrator. Windows 7 Pro 64-bit. I unstalled the CCC and download the 92.3MG Calalyst suit after loading I recieved the same msg. CCC not working. I checked and still have 90ba9c70f846762e Token.

  42. I am having the same issue as Junkrider have, getting access denied when i try delete, i am administrator. Windows 7 home premium 64-bit

  43. Junkrider says:

    I tried but I am getting access denied. Windows 7 Home Premium SP1 64-bit. Only one user created with password and confirmed as administrator. Tried to delete. Tried to right-click and select un-install. Tried to remove the read-only attribute at the folder level. All say access denied.

  44. Hey man,

    I wanted to delete the 90ba9c70f846762e in my Assembly, but i cant. I did remove the CCC and all the other ATI stuff. What now?

  45. I dont have said Public Token 90ba9c70f846762e in my Assembly. What now?

  46. I wish I had found this tip before I spent 3 hours monkeying with uninstalling and reinstalling everything ATI and Microsoft .NET with no success, this just worked!

  47. Thank you kindly, sir. Worked like a charm.

  48. Hey, it won’t let me delete them. What do i do?

    THX for the help

    • You need to make sure that 1) you are logged in as a local admin and 2) remove the previous CCC program through add/remove programs.

      • finaldriver says:

        i want to make a youtube to help other people that have this same problem so if you have a skype hit me up

      • Hi,

        I DID completely remove previous CCC program
        i AM logged as an admin (in fact im the only person using my PC)
        STILL i cant erase those ati-related public tokens (i always get the access denied message)

        Any ideas? Btw im a noobie so i COULD be doing something basic wrong (i dont understand why that adminstrator thing was created at the win 7 installation anyway, since i never asked for it. No one but me uses the PC)

  49. It worked for me! I admit I was afraid that this would hose my system as I really didn’t understand what these keys are for. Technically there isn’t an option given to delete the tokens, rather you uninstall them when you right click on them.

    • Bhindi Bhajji says:

      I didn’t have the Public Token, but an uninstall of CCC + Ati Drivers (in Device manager), deletion of all Ati folders in Program Files & Program Files (x86) and a cclean has sorted it.
      Oh and the hiding/unhiding of the Users folder for good measure!!

      What a pain!!

      Thanks mate!

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