Ok do this. Boot to safe mode, click on start, then run, type msconfig and hit enter, click on the startup tab and uncheck every box and click on apply, then ok and restart the pc. Then see if the system still freezes. I would also suggest doing this first. Lets get a list of whats running at bootup. Boot to safe mode with networking and do the following.
Download the
HijackThis installer from
here.
Run the installer and choose
Install, indicating that you accept the licence agreement. The installer will place a shortcut on your desktop and launch HijackThis.
Vista and Windows 7 users must right click on the hijackthis icon and click on run as. If the run as option doesn't appear then press and hold the shift key while right clicking on the icon to get it to appear.
Click
Do a system scan and save a logfile
Most of what HijackThis lists will be harmless or even essential, don't fix anything yet.
When the hijackthis log appears in a notepad file, click on the edit menu, click select all, then click on the edit menu again and click on copy. Come back to your reply and right click on your mouse and click on paste.
Post the logfile that HijackThis produces