Start the Recovery console or..
Start the computer with the boot disks or Windows CDROM
After the Welcome to Setup dialog box appears, press R to repair, and then press C to start Recovery console.
Choose install Windows and log on as Administrator.
At the command prompt type "disable Mup.sys"
"MUP stands for "Multiple UNC Provider" which assists Windows in locating resources when more than one redirector is on a machine such as "Microsoft Client for Microsoft Networks" and the "Novell Client for Novell Netware". When a connection to a server is requested it does not know if the request is to a Novell server or an NT server. It will start looking for the server with the primary protocol on the primary requestor and then continue looking for the server on each protocol bound to each redirector until the server is found."
The other suggestion:
1, Start up with recover mode,
2. Run chkdsk /r. Does it work. if not
3. Check up BIOS setting. Restore to safe mode
4. Have you had any new device installed, startup with the lease ammount of peripherials possible