Freezing computer

Hi
Running Windows 7 home premium.
It's a Dell computer about 4 years old and no probs apart from the odd malware infection. In the last couple of days it has frozen up, the curser will not move and there is a small square under the curser that looks like a colored bar code that flashes intermittently and the busy light not on at all. I have to push the power button to force a shutdown. Have run malewarebytes but nothing found, then this morning just browsing the net and it just crashed, like there had been a power cut it started to restart and just stopped loading and would do nothing until I pushed the power button to force a shutdown, left for a few hours and now working ok.
Just worried that its telling me something is going to fail, like the hard drive.

chubb3g114

 

You may try running chkdsk to check for possible file system errors or corruption on your drive.