If your computer is freezing up right after logging in to your profile, then there is something causing the system to freeze on the start-up. Most applications have the option to run at start-up by default, most people don’t bother to uncheck the option when installing the application, so they end up with a track load of applications loading at the computer start-up, and some of those applications are not that benevolent at all. Take weather bug for example.
The first thing you should do is booting up your computer in Safe mode, probably in this mode the computer won’t freeze. You normally get to the safe mode by pressing the F8 or F10 key on your keyboard while the computer run POST ( when it ask you to press certain key to get to the BIOS) . Once you get into safe mode on your computer go to Start and click on Run type msconfig and press OK. that should get you to the System Configuration utility. Click on the startup tab and uncheck everything you don’t need to load at the startup. Probably you will only need to leave the Anti-virus to run at startup and remove all the rest. I know I know what you are wondering, should you leave spy-sweeper and all the crap you have downloaded from the Internet thinking it would make your computer faster? Well, I can assure you they don’t do anything else but slow your computer. Click Apply and then OK and reboot the computer. Let it start as it normally does and see if it freezes up this time.