Description of the Windows XP Recovery Console
you may of installed a bad drive or picked up a viruse,have you tried a a system restore to b4 this freezing started?
Sounds like there might be a problem with the MBR (Master Boot Record) it is absolutely the first thing that processes when a computer is turned on, and if there is an error when booting up, a lot of the times you have a bad sector somewhere. Trying finding a relatively new harddrive and swap them out temp. If that solves the problem then you know your hard drive has crashed. Another thing that may have happened is that you have some how got a virus, try to boot up in safe mode then run an anti-virus software and see if that catches it.
Could be a problem with device drivers , hardware or software . This problem can be solved by uninstalling new softwares, updating device drivers and making minor configuration changes