Freezes are random events and are difficult to diagnose, especially since they usually don't produce error messages.   But since it happens when you are browsing the internet, one possibility is spyware and internet parasites.  See the message from ChrisRLG in the yellow area at the top of this forum and see if getting rid of spyware helps to resolve this issue.

Steve

if one of the computer's fans--case fan or processor fan--isn't working it can heat up and cause freezes, on the internet is maybe where you're using it most.  you can go into bios and check the temperature, or open the case to check the processor fan.  the case fan you can check by putting your hand at the top back of the computer to see if air is coming out.

a bad video card or one that's heating up could cause a problem, too.

one easier thing to try--from the control panel, internet options, clear history.  then click to delete files and when the box comes up put a check in it , click yes to delete all offline files.  this may take a few seconds.  then click okay.