Installaion error

i have vista installed but now i want to installed xp.but when i run setup after somtime a msg show on a blue screen, like that:-\r\n(The problem has detected and windows has been shut down to prevent damage on your computer. \r\nIf this is the first time you've seen this stop error screen, restart your computer.
If this screen appears again, follow this steps - the device driver got stuck in an infinite loop.
This usually indicates problem with the device itself or with the device driver programming the hardware incorrectly.
- STOP: 0x000000EA (0x845F7200, 0x00000000, 0x00000000, 0x00000000)).
So, that's the error message who came up every time I start my computer.
So, it doesn't finish the installation because this error appear.

pleaese tell me what i do