When I try to run a cd-rom from a magazine I get the message " 16 bit windows subsystem. WINDOWS\SYSTEM32\AUTOEXEC .NT The system file is not suitable for running MS-DOS and Microsoft Windows applications. Choose close to terminate the application." It worked fine yesterday, also when I opened Photoshop a message said my computer had made changes and I had to re-register. Ihave not made any changes. OS is XP. Please help.