|A complete reinstall of the Operating System and third party programmes after backing up your personal files onto a USB pen.|
In future run your browser in a sandbox; e.g. Sandboxie (www.sandboxie.com) or in Kaspersky's own Safe Run for Websites.
I had a similar experience while running Firefox 4 in Kaspersky's Safe Run for Websites. Firefox and the Safe Run for Websites suddenly disappeared and I got a message saying that Kaspersky had been unloaded from Memory. The red Kaspersky icon in the bottom right tray turned grey, but very quickly turned red again.When Kaspersky was unloaded from memory the sandbox in which Firefox was running ( Safe Run for Websites) and Firefox closed and with it the route of the cause of the unloading of Kaspersky; this closing of the sandbox also probably isolated any infection. I then deleted the contents of the sandbox ( Safe Run for Websites) in Kaspersky. I then ran Kaspersky in Safe Mode and it found nothing; also I ran Malwarebytes in Safe Mode and it found nothing. I also have Prevx 3.0 and Microsoft Security Essentials which registered nothing whilst in their realtime infection monitoring modes at the time of the crashing of the browser and Kaspersky. My PC is working fine and believe that my sandbox saved the day.