I've been running Windows8 on my laptop for quite some time now. The only times I've ever seen it freeze like that is when the hard drive is failing. I've had to repair it twice now and I'm going to get a new SSD to replace the 2.5 year old one which seems to be done.
Personally I'd go look in the error log first as this is the most likely place to find what is causing the freezing.
Press the windows key and R together to get the run window.
In the run window type
mmc c:\windows\system32\compmgmt.msc
Click on OK.
In the computer management console open the event viewer (Click on the triangle on it's side next to it, it will roll over and open the tree, turning black in the process), open Windows Logs the same way.
Click on System.
You are looking for events which have a yellow triangle or a red circle. You can read the error messages if you get one.
If you see nothing in system, you could also try looking in the Application one, but I find that it's usually system.
Here is an example from my computer with the problem I'm having with the C drive highlighted.
The reason I suggest using the winkey+r combination is that in W8 Microsoft have made it damned hard to get to computer management and this is the fastest way I can think of getting there.
Just as a thought, which explorer are you using? The so called modern UI one that takes over all the screen and has to scroll bars or the normal windows one you get to from the normal windows desktop??