Boot Scan resulted in corrupted system; cannot boot into windows

[edburdick]

I am a new user to Avast; did a webinstall and a scan on my Vista Home Edition lapto.  Lots of adware and PUPs but the system  has been running great for a couple of days.   Today Avast prompted me to (optional) do a scan during the early boot stages prior to initializing Windows.  I thought this was a good idea and started the scan.   It ran in DOS mode windowing with several flagged items and an option list of 1 to Many for action to take.   I opted for "1" and continued the scan.   Somewhere in the scan process the laptop powered down and back up with a massively failed DMI The desktop had lost all but a few shortcut icons; my email was corrupted; three browsers had no history; ?Firefox in particular was hammered the worst in that I used master passworded storage.  I googled and first off it appears I may have awakened a sleeping rogue.   I do not know what to do at this point without making the situation worse.  Any advice or help?

[Pondus]

for virus problems, follow the sticky guide "Logs to assist with cleaning malware" found at top in Viruses and Worms forum section

[Eddy]

What exact version of avast do you have?

If you have/had a lot of malware on it, the system did not run great.

Do you (or did you) have other malware removers installed?
If so, which one(s)?
Did you remove them?
If so, how?

Please answer the questions so that we know more and we can help you better.
Also please follow the instructions as mentioned here:
https://forum.avast.com/index.php?topic=53253.0

Do not change anything on your system, do not hookup a usb stick or something till we have analyzed the logs.