Monitor displays message and cannot use

monitor says : self test, monitor is working, check video and pc cables.
and it says this whether the pc is on or just the monitor. i have no access to anything so there is no safe mode or anything. stop:0x0000007F
any suggestions?

Stop 7F is typically a memory error. If you have several memory strips, take out all and insert one at a time to see if Window boots with any. Other possible hardware faults are motherboard or video card. Since you give absolutely no hardware or operating system details it is at the moment impossible to advise. You should also appreciate that some history leading up to this fault is essential. Please read http://www.techspot.com/vb/topic33297.html especially the example 'Brand new PC is crashing' which concidently is about the same crash code.......

very sorry, i am using windows xp with a pentium II processor.