This does sound fatal.
All you can do is get everything off it you can, i normally do this by using a bootable cd rom such as Barts PE.....this is a safe way to get the stuff off onto a memory card or cd but beware or transferring the virus too!
UBCD for Windows is also good.
But this is VERY techie......
Anyway, good luck.
Fatal indeed algy...well im back in business so tyvm for all your advice/replies guys but none of them worked..tried the repair option one last time and still nothing.
So i did the honourable thing and put it out its misery but i managed to get all the stuff i wanted to keep onto my media centre/external HD..all the important stuff like my fruity folder and the 20 odd GB worth of pron .
Still never got to find out what the virus was or where it came from or where it was hiding..(everywhere i presume) but TBH it was a pretty fookin good one..fooked ma PC up no end.