Try installing it once more in <SAFE MODE>. Be sure your drive is defragmented before you do.
Do you have ample free space? CS3 requires 17% free space at a minimum after the install?
Damaged CS3 install disk?
Any old versions on that computer? You might benefit from Downloading the simple RegCleaner from www.majorgeeks.com and removing all old references to Adobe Photoshop.
Your best bet is to call Adobe support. They provide free installation help if you buy any of their programs. I'm pretty much having the same problem right and I've posted my question in every tech forum I could find, no luck.Make sure you call Adobe on a day you're free. Their customer support is seriously needs some improvements.
Here's some solutions I've found but none worked for me (although it has worked for some people)
Make a manual System Restore point, so that you're able to rollback in case you screwup...
Uninstall every single Adobe program you find, including CS3, CS4, even Adobe Acrobat Reader
using the Control Panel, Add/Remove Programs.
Get the "cs4clean" script from Adobe's official support website
and run it to see if that helps, reboot if needed.
Create another System Restoration checkpoint, just in case.
Here's how to manually eradicate all traces of a program, Adobe in this case:
Go into %ProgramFiles% and eradicate any directory called Adobe...
If it tells you the directory cannot be deleted because files are in use, rename it to "xxx" and you'll be able to delete "xxx" after the next reboot.
Note: Vista 64-bit users also need to do the same in %ProgramFiles(x86)%
do the same in %CommonProgramFiles% -- and %CommonProgramFiles(x86)% on Vista 64-bit
then in %AllUsersProfile%
then in %AppData%
then in %LocalAppData%
It's also a good opportunity to delete all temporary files located in %Tmp% and %SystemRoot%\System32\Temp
(don't worry if a few cannot be deleted because they're still in use)
- Launch regedit, and inspect
both branches HKLM\Software and HKCU\Software
if you spot a sub-branch called "Adobe",
Also, remove anything referencing Adobe in
Also check the start menu, All programs, Startup... delete any Adobe icon there if there's any.
You can also run "msconfig" and verify in the Startup tab that you didn't forget anything.
Personally I also manually eradicate the Macrovision "FLEXnet Licensing Service" license manager service that Adobe is installing with their products, because it's probably the root of all activation evils:
run "services.msc", STOP the service, then set it to Startup=DISABLED.
*IF* you know what you're doing, eradicate it from the registry at HKLM\System\CurrentControlSet\Services : delete the branch called "FLEXnet Licensing Service" -- but so do this only if you know what you're doing because it's very easy to screw up your computer here
Also don't forget to purge "%CommonProgramFiles%\Macrovision Shared"
-- on vista 64-bit this directory is located at "%CommonProgramFiles(x86)%\Macrovision Shared" instead.
In case it tells you the directory cannot be deleted because some files are still in use, use the previous trick: rename it to "xxx" and you'll be able to delete it after the next reboot.
Reboot and cross fingers
If you screwed up your computer, boot in safe mode (hit F8 when at the BIOS screen/logo) and System Restore it to any of the above checkpoints when it was still OK...