Can't open Photoshop 7

Question

I've used Photoshop 7 for 2 years without problem, using Window xp. Starting 3 days ago I could not open Photoshop 7. The message says, "You currently have Adobe Photoshop's primary scratch and Window's primary paging file on the same volume which results in reduced performance. It's recommended that you set Adobe Photoshop's primary scratch volumne to be on a different volume, preferably on a different physical drive." Another message says, "Adobe Photoshop could not initiate Photoshop because the file is locked. Use the "Properties" commend in the Window Explorer to unlock the file." I got into the "Properties" of the Window Explorer but did not know how to "unlock the file". Please teach me how " to unlock the file" I also unintalled the Photoshop 7 and reinstalled it after I closed dowm the computer for some 10 minutes, without success.
I will be most obliged if you could be so kind to teach me in detail step-by-step how to open the Photoshop. Many many thanks to you.

Answer 1

First reset the preferences (an uninstall/reinstall cycle doesn't do this as the preference file is created after installation).
See the forum FAQ for details. Or manually delete Photoshop preferences.psp (out of my head) in the Application Data folder.
Then the message about the primary scratch, although it's meaningful, this won't prevent you from using PS. The program uses a "scratch volume" (a bit like Windows Paging File). When this volume is on the same HDD as the real Windows Paging File (the virtual memory) PS and Windows will sometimes "fight" for read/write access through the same heads of the same disk.
However, when the scratch volume is on one or more physically different HDDs (configurable in PS preferences) it can clearly speed things up.
You can, however work with all on the same disk, if you have to.
A way to get rid of the message during program launch is to assign C:\ for the scratch disk in stead of the default "Startup".
P.S. when you add a HDD for this purpose use an internal IDE or SATA. Not an external drive. An external has much slower access rates, and could slow down your system more than it is now.
Hope this helps.
Rob