(New here. Read the intro posts.) Computer in question is running 64-bit Windows 7 with Service Pack 1. Infection is on a non-Admin account. Series of events:
Computer suddenly displays Mandiant warning saying the computer accessed forbidden info (child porn, file-sharing, etc. Nothing like this has happened.). Wanted $300 to remove the block.
Attempted removal using Option 1 found here: https://www.bleepingcomputer.com/virus-removal/remove-mandiant-usa-cyber-security-ransomware
(Restart into Safe Mode with Command Prompt > rstrui.exe > Only one restore point was available from 8/27 > Start comp in regular mode. DL Malwarebytes Anti-Malware Free > Start Quick Scan > System Care Antivirus pops up during scan and appears to stop MB scan.)
Then attempt to follow SCA removal tips found here: https://www.bleepingcomputer.com/virus-removal/remove-system-care-antivirus
MB Chameleon unzipped to an empty folder.
Downloaded RogueKiller. Found plenty of infections but that's when Zero Access popped up. Website said RogueKiller should fix it. Didn't. Access is denied to infected files.
Another site suggested Kaspersky TDSSKill would help me get around this. However, it says "Can't initialize log" at 5% and then "Can't load driver" at 40%.
I am at a loss as to where to go from here. Thanks again.