Enabling Installation of CS3 and CS4 products that will not install on Windows 7 64Bit.

Question

Adobe installers are not known for their helpful or forgiving ways & I have more than once had to reinstall Windows when installation of CS3 and CS4 products has failed with patently inscrutable errors.
The background to the current issue that I was attempting to install PS CS4 on a W7 system which already had CS CS3 installed. The CS4 installer threw up inscrutable messages indicating  that the installation could not proceed and to contact Adobe (they are joking right ? Their phone & web support is notoriously UN-helpful).
After reading through threads suggesting that I uninstall CS3, apply CS3 and CS4 cleaning scripts I was in exactly same position I have found myself in on least 2 occasions with WinXP. By this time I couldn't event get CS CS3 to reinstall!
Then I decided to review the event log and found a number of installer events thrown up by the Adobe installers resembling "Error 1402. Could not open key: UNKNOWN\Components\xxxxxxxx".
I tracked down this very helpful solution which allowed me to change the registry permissions on the parent key HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Installer\UserData\S-1-5-18\ Components and propagate the new permissions down to the child keys.
http://www.okino.com/conv/changing_windows_registry_permissions.htm.
My advice is to follow instructions for "A More All-Encompassing Solution" and propagate the permissions right down to all the child keys as I could see a number of separate adobe installer errors in the event log. Also note the instruction to change the Owner from 'System' to 'Administrators' in Advanced settings. This is necessary in order for the Permissions change to be accepted and replace all the child object permissions.
As with most registry changes good advice to backup your registry hive first (although I didn't; by this time I was already expecting to have to reinstall Windows) and restart your system after making the registry changes before attempting to install  / reinstall CS3 or CS4 products.
Hope this solution works as well for others as it did for me as the Adobe support on this issue has been next to useless.
[P.S. Q: Did you hear the joke about the guy who worked on product installation at Adobe rocking up at job interview with 'Adobe Installation Project Team' on his Resume? A: That that is the joke! If you wanted another job in installation development you would hardly admit to experience at Adobe ;)]

Answer 1

John Joslin wrote:
We don’t want people messing with the registry when they don’t need.
My apologies John I didn't realize that I was addressing the official custodian of Photoshop.
Incidentally my advice is intended for others in a similar situation who find themselves stalled during installation and otherwise contemplating a re-installation of Windows. I believe this would be obvious to most forum participants who had actually read my original post.