That "about:blank" is nasty. Ive had it before too. Its some kind of trojan type spyware, not a virus that destroys your hard drive. It just eats memory though so makes browsing slower and annoying.

If you knew the exact day you got it you could search your hard drive for files changed or created on and after that date. I believe I manually deleted a bunch of files in the system folder but you need to know what your doing.