Just a short selection of Adobe articles that can help you to troubleshoot some problems you might have with Adobe Photoshop CS3:

Adobe ImageReady CS2 feature location guide for Photoshop CS3

Troubleshoot system errors or freezes in Adobe Photoshop CS3 on Windows XP

Troubleshoot system errors or freezes in Photoshop CS3 on Mac OS

Optimize performance of Photoshop CS3 on Windows XP and Vista

Optimize performance in Photoshop CS3 on Mac OS

Troubleshoot installation problems in Adobe Photoshop CS3 on Windows XP

Troubleshoot installation problems in Adobe Photoshop CS3 on Mac OS X