Windows 7 Troubleshooting Random Computer Freezes on Windows 7: Seeking Help with Specs and Solutions

Before looking at your existing problem I would advise you to stave off another problem waiting to happen - when (not if) you need to reinstall your system and you have no means of recovery from a serious problem or from a crashed hard drive. Even though the system cam pre-installed you should have a recovery partition on your hard drive from which you could recover a system crash but not a complete hard drive failure You should also have the means to burn recovery disks from the recovery partition and I would strongly recommend you do this - see your user guide or check with the supplier. If at the worst your pc was not supplied with any means of recovery you should consider making your own provision for it using something like Acronis True Image to generate your own system image.

For the current problem I advise you run a system restore to some point predating the problem occurring then carefully monitor any system updates or fresh installs which might have caused it. You should set your windows updates to advise you of what is available and let you select what you want to install so you know what is happening. I would reject any automatic driver updates - I always check for driver updates myself from the manufacturer's website rather than allowing automatic updating of drivers which have been known to cause problems.