1 XP system in use by multiple accounts

I have created a Windows XP system and placed this in "/Windows/" i.o.w. in the root directory. I want this system to be used by multiple users on this system. (not simultanously but consecutive).

However only 1 user (the original) is able to use it all others have a problem (message "P. failed to allocate specified ampunt of memory ....... go to preferences and select 'enable virt. mem. preallocation"). I do that but the error remains.


So how can I use the same Windows system from different users?

 

see Parallels Desktop for Mac user guide from http://www.parallels.com/en/download/file/doc/Parallels_Desktop_for_Mac_User_Guide.pdf page 235