Adobe has a nice article in it’s knowledgebase, that helps to prevent unintentional slowdowns in program performance,
caused by applying the wrong settings. Applicable for the Windows version.

I adjusted mine and did find an improvement, though I already had set most of the suggestions by myself.

However – If you just installed Photoshop and haven’t looked under the hood – it sure is worth giving it a try!

Adobe: Optimize performance of Photoshop CS3 on Windows XP and Vista

Info: I found this link on another blog – however it led to yet another, that one to another blog, so
I decided to break this annoying circle and to post the link directly to spare you wandering around.