Issues with software, windows unresponsive/not running correctly

It started with just youtube and firefox not working properly. For example I could not pause a video or adjust the volume. I tried Chrome but that was worse, I could not even go to a new tab. VLC Media player refused to pause. Cubase 6 was not showing any recent projects and refused to peform various functions.

I went to check if I had a virus but by then my computer was to unresponsive to even press 'scan'

What has happened? and any ideas on how to fix it?

EDIT: Everything works fine in Safe Mode

Probably a virus or trojan.

Install malwarebytes antimalware in safe mode with networking, update and scan.
Then use Dr web, cureit to scan for viruses.

That's basically what i do, but no guarantee though. Better prepare for complete installation again :/

Try running:

• Microsoft Security Essentials - Microsoft Windows
• Anti-rootkit utility TDSSKiller

Delete any files or programs it then detects; please post back your results.