Hi I have just fixed my computer- I think !
First.
Click control panel> system> advance system setting> advance(tab)> settings> advance> change> click custom size> min allowed (I set my to 500mb)> max allowed ( I set my up above what is recommended by the computer 7000mb, this is on the bottom of window)> restart computer.
You see may not have enough virtual memory ! not be confused with RAM.
If it happens again
second
click on start> start search type in cmd> press enter>this opens the administrator C:\Window\system32\cmd.exe window>
(This window could be black) and immediately after C:\Users\Users>
- Type ipconfig /release, and then press ENTER.
- Type ipconfig /renew, and then press ENTER
To verify that address conflicts have been resolved:
click Start> in Start Search type cmd> press ENTER.
To verify a DHCP client lease, type ipconfig /all to view lease-status information.
The output of the ipconfig command should show an IPv4 or IPv6 address marked "preferred.
you see the computer "thinks" it's on a network and is trying to contact "administrator" when this doesn't happen it freezes.
hope this helps because it fixed my computer- well it hasn't froze (hard-lock) since.