I'm trying to fix a computer from a friend, which has for some unknonwn reason installed the 64bit and 32bit version of CS4. The 64bit version does not work, the 32bit does.

However it seems that the 64bit version was the first installed one, associations to the .psd files are going to the 64bit version.

There seems no way to create an association with only the 32bit version. When I select open with` and I browse to the 32bit version and select open, it does not get added to the list of applications?

Update:

Unfortunately the problem just went away. It's annoying as the root cause is likely never to be found, I'm accepting Fopedush's answer for this "detailness".