Blank screen and cursor only

Have had laptop for 3 months with no problem. This morning when powered up all i am getting is blank screen - doesn't even get to log in screen. Cursor is there and can be moved. Have tried FcnF8, but nothing changes. Same for CTR-ALT-DEL - nothing. Only difference yesterday is that bought Bullguard and installed after 3 month trial ended. I am running Windows 8.1.

Any thoughts?

I've seen this happen once before on my previous PC, it was actually because I was busy swapping hard drives around, and whilst swapping stuff around it actually ended up that first in the boot list was a USB device I had plugged in, therefore it had nothing to boot from.

So you may want to hop into the BIOS when you start the machine (often accessed by pressing F2 or DEL - may be different for your machine) and check out the boot list, make sure your hard drive is still first on the list, if not, change it to be first.