I have a hp pavilion ze4900 laptop. I thought it had Windows XP on it. Now I am not sure. I want to run some windows 95 and 98 computer games. Whenever I try to install them it says... C:|WINDOWS|SYSTEM32|AUTOEXEC.NT. The system file is not suitable for running MS-DOS and Microsoft Windows applications...I am computer illiterate. Someone told me I had deleted files that are required to fix the problem. If so, how do I do a 'wipe out' of my system to start again?