First thing is you need to be quite specific about where the boot up sequence fails. Sounds like you are actually booting the OS and reaching your account prior to the failure. Next you need to specify precisely what OS you are running and the version for example, Windows 8 Pro. We also need to know basic hardware information, such as 32 or 64 bit etc... Any error messages.I'm sending this from my phone.
ive turned my computer off and on 3x now, every time it's on for like 5 minutes then freezes and the mouse won't move. And no matter how long I wait nothing happens. The only thing I can do is click ctrl alt delete, and all that does is let me use the directional keys to choose "switch users" then when I switch it just freezes that one.
does anyone know what to do?
If you can get to that screen and the machine does not shut itself off it's not a thermal issue. You can try a bios reset but if you can boot your OS and reach a user account my guess is you are failing at a much higher level.
If you are on a MS Windows box try holding F8 during the boot up and booting into safe mode with networking (if you can). If you can't and you've recently installed any software boot into safe mode and remove it or return to a previous restore point (assuming again you are windows and you made restore points). Anyway after finally booting into safe mode with networking go here and download and burn a rescue disk or burn a USB stick (there you are own your own as I don't have the time today to explain how to make a bootable USB).
Kasperky rescue disk:
http://support.kaspersky.com/4162
Make that then in safe mode reboot and clean up.
If you aren't on Windows give me the specifics about your OS.