BSOD during startup on Dell Studio laptop? (read description)

On a Dell Studio 1535 laptop using Vista, after the startup scrolling bar disappears from the screen (via selecting “launch windows repair utility”; selecting “start windows normally” results in an indefinite scrolling bar.), there is an approx. 2 minute pause, followed by a BSOD portraying the following message, excluding the “a problem has been detected” dialogue crap:

*** STOP: 0×000000F4 (0×00000003, 0×83F79020, 0×83F7916c, 0×8128C330)

Our family believes a virus had infected our PC earlier, so consider that as well.

Also, there earlier was a stop code 0xc0000021a or something.

PLEASE HELP!!!