I inadvertently renamed the psapi.dll file found in my Windows/System 32 (along with all the other psapi.dll files found by doing a search). I did this to try to eliminate the popup error I get after I loaded Internet Explorer 7: "The procedure entry point GetProcessImageFileNameW could not be located in dynamic link library PSAPI.DLL." Now my Toshiba laptop with Windows XP will not boot. What can I do to fix this problem?