Programs freeze because XP messes up. It happens to everyone. The best you can do is reduce the chance that XP will mess up by running the disk cleanup in accesories, defragment monthly (also in accessories) and get a registry repair program. The free version of registry repair by glarysoft.
Your first option should be to run Windows Update. Also check your computer for spyware, viruses, and adware. Some good free options include Malwarebytes, Spybot, and Microsoft Security Essentials.
There can be many reasons through which your computer could be freezed. May be your CPU is taking too much memory to process the task or might be some issue with a virus.
Your problem may be your registry files, get a registry scanner and repair your computer to see if that helps. After youy do this, make sure that your OS is up to date, to do this simply run windows update.
