Run your task manager and check what the CPU and memory usage for Solidworks is. If it is indeed Solidworks thats causing your machine to freeze, my guess is that your memory usage should be maxed out.
Also, have you tried running Solidworks in both Safe Mode and Open GL mode? (You can do so using Solidworks Rx which you'l find in your start menu under Solidworks Tools.)
Also be sure there is no other component on the computer starting to fail. SolidWorks will push computer hardware to the max and will have issues, while other software that doesn't push your computer as hard will work fine.
I had my Var look as my pc and they found that the hard drive was causing freeze issues and even blue screens.
This hard drive was less than a year old and so I never thought of it.
These freezes and blue screens only ever occured when using Solidworks.
I have now installed one of those Seagate 750Gb hybrid drives and so far no more freezing or crashes.
Worth a try!