Looks like the system is trying to boot through a network which might mean it can't see a system on the hard disk.
That may be failing so try starting the machine with a Windows DVD if you have one.  If you can get to a stage where you can see a Command Prompt, run Checkdisk with the /r switch to fix any errors it finds.  The syntax at the prompt will be
chkdsk /r
then hit Enter.