http://www.poegasm.com/computer-round-off-error/

Computer boot up error?
Hi guys my problem is this:
My partnet has just bought their computer round and when we connect the moniter and boot up the PC, it gets to just past the Windoes loading screen, flickers and goes off. The hard drive lights are still on. WOuld this call for a new installation of Windows, or is there another fault?
Computer stuff:
Moniter- Dell, no other brand/number on it.
PC: Custom built in a Hi-Grade case.
Ram 512mb
OS: Win XP/SP2
GFX: Nivida GFX card, not sure on the model.
Thanks in advance.
It would likely mean that a new operating system would need to be installed, however, I would try BOTH of these things first:
1. While booting, depress the f5 and f8 keys. If a screen comes up to do so, select “last known good”, and hit enter. Try the same thing again for “safe mode” also, which will help to see if you have hardware/software incompatabilities.
2. Try doing a repair of the operating system if you have the original operating system CD.
In NO cirucmstances should you throw money at the problem by purchasing a Windows Operating system CD. Instead, get a good, stable, secure open source operating system such as www.kubuntu.org