While working in Outlook I left a msg on screen and when I came back from dinner the screen said "Operating system not found on any device or drive" I restarted the computer and it instantly goes to this same screen. Nothing new has been added to the computer. This is a compaq desktop.

uh?? That doesn't seem to make any sense at all, I thought I'd heard it all.. but I guess not. Ok did you reboot afterward ? gimme more details please...

Check and see if there is a flopy disk in the driver.

if its not a floppy or cd in drive try this link
m.e wont start
http://computing.net/windowsme/wwwboard/forum/30687.html