When i turn on the computer, it comes up with an error saying:

Chassis intruded!
Fatal error...System Halted.

HOW DO I FIX THIS

First, make sure there is nothing in the way of the cpu fan, then close your case.

start the pc up, spam f buttons or delete to get to the bios, then look for "Boot" see if there's anything about errors in there. (I'm assuming all BIOSes are laid out somewhat similar to each other)

Ah, yeah, I remember now (thanks Nannal).

The chassis intrusion alarm is something that's rarely included these days, but I believe it works by simply closing a circuit when the sides of the case are on. Simply go into the BIOS (spam delete at startup, the part where it beeps) and look around to see if you can find an option to turn it off/ignore it (or an option to ignore all startup warnings).

(Disclaimer: The above info may be BS, apologies if it does not work)

This is still common in HP Compaq and some Dell systems.

If it's any help, my pc wouldn't startup if there was no keyboard before i changed it.

that could be quite useful though nannal

No it couldn't!

Yeah, it's an alarm similar to that

not for the casual onlooker I grant you

No, It just couldn't be useful!

Thanks Nannal. Ok it boots up now, but gets to windows XP page start thing lol and they keyboard and mouse stop working, then keeps on restarting So homosexual!

Not that anything is wrong with being homosexual... *cough*

safe mode it.

get to desktop.

restart it.

enjoy.

IT LIVES!!!!!
Almost 6 months without the working computer
IT IS FINALLY ALIVE!!!

Thank ya <3

cool stuff. Now get everything installed