PC freezing after short period

The last 2 days i have noticed that after around 30mins or so i can no longer open files/internet/pics etc

Nothing can be opened but window tabs can be minimized and have full use of mouse and keyboard.

I cant open task manage when this happens and only a restart works.
This can only be done manually via the reset button on base unit and not via Windows restart function.

Ive run full AV scan with MSE and came back clean.

Not installed any programs within this time, the only thing that i can think of updating was Firefox 2 days ago.

many thanks for any help

If you created a System Restore point prior to updating Firefox, you could use that restore point to roll back your system.

If you don't already have it, and can get on the web (or otherwise place a downloaded installer on the problem computer), you should try a full scan with Malwarebytes after allowing it to update.

Ok not sure what's happened but after latest freeze and restart the pc won't go past the welcome screen it appears to boot ok then after it says welcome the screen goes black with only the mouse pointer showing

I've tried system restore in safe mode but I eat a message saying its turned off I have tried turning on through one of your guides via System Policy but it won't turn on.

At moment all I can access is safe mode and only Internet access is my phone right now

Any help greatly appreciated

Wow really nooooooooo

No way of getting system restore turned on other then methods described in the link?

Boot into System Recovery Options to run a few Startup Repairs, which should offer to automate System Restore. If not run it from the Options list.

If this fails work through these steps for Troubleshooting Windows 7 Failure to Start.

You mentioned you'd run an AV scan but said it was Malwarebytes which is NOT an AV. So I would start with the WDO or one of the other bootable AV's provided in tutorial.

If you're running less than a perfect install now would be a good time to invest in one since you have the assistance of the top resource on the web for it. Look over these steps for Clean Reinstall - Factory OEM Windows 7 which assure a perfect install even for retail.

Ill check those links thank you

I did run AV with Microsoft Security Essentials
The reply I had was to run malware bytes but I only got round to installing it before I had to restart.

Ok I ran the Repair function from System Recovery Options it said there was no problems

I then selected System Restore but was told System protection was not turned on and I could not go any further

In the process of running full scan with malwarebytes

2 full scans with MSE and Malwarebytes have come back clean.

I've attached pic I took of what comes up when I try to select system restore
Now when I click the link that says Turn system Restore on it the steps they suggest aren't there

Proceed with the steps including the hardware tests in the beginning note of Troubleshooting Windows 7 Failure to Start to confirm the hardware first.

You said you couldn't boot but now are working from the desktop. If so work through these Troubleshooting Steps for Windows 7

Both WD Data Lifeguard and Seagate Seatools HD tests as well as memtest RAM test are on Hiren’s BootCD 15.1 which ISO can be burned to CD using Windows Image Burner or written to flash stick using Universal USB Installer with Hirens in the dropdown menu.

If all of the steps fail then copy out your files and run Factory Recovery or get the superior Clean Reinstall.