Windows cannot access the specified device, path, or file

[Guest Pops]

WinXP SP2. Running fine one moment, then started receiving the above error

when trying to run programs.

 

Rebooted, and seemed OK up to the user icon screen. Select a user and

again appears normal upto the loaded "tune". After a short while hear the

"Dong" (problem sound). No user programs load. Can access the Task Manager

via CTRL/ALT/DEL, which shows "System" and "Network" processes running.

Only taskmgr.exe and explorer.exe show as user processes.

 

Can open Windows Explorer via Start menu or desktop icon and can navigate

through all folders and see all files, just cannot execute anything.

 

Tried a google from my other machines and posts abound, but many talk of an

IE6/7 problem, which I don't use, and others say add/delete this or that,

but I can't!

 

HELP!?