I have Windows 7 Home Premium. Dell Studio 1558 4gb of ram 64bit operating system. Intel Core i3 CPU M350@ 2.27GHz. Recently had a problem with the two other user accounts not being able to be logged into. If the account is clicked it shows that it's starting, and then immediately shows it logging off. It returns to the user account screen showing all users. I thought maybe it was something corrupt in one, but noticed it in both. If I delete the account, and re-create one, the same thing happens right away. However, my account which is the administrator has no issues. It starts up just fine. No problems. I've tried to see if this is a problem in safe mode and it is. I've run malware-bytes anti-malware. It doesn't find anything. I've used spybot which comes up with nothing. However, I downloaded comodo cleaning essentials. I can get it to update but when it searches it disappears after 1%. I've tried to use it from my flash drive, and the same thing happens. I try to go into my account in safe mode and run it, and the same thing happens. I've tried AVG which I have on my computer and all user accounts. It does the same thing. Starts searching finds like 5 rootkits, and I clean them. I restarted. No change. I do another search with AVG and this time it says it finds 7 rootkits. It tells me 7 potentially dangerous threats - not all were removed. It tells me some items require my attention. I click to remove and reboot computer. Nothing has changed. I did an internet search and someone had a similar problem, and the only way they could get into the other user accounts was to make them administrators. I will not do that. I'm not really sure how I got the virus. One of the user accounts was for my niece. Internet was disabled. Only windows kids games on there. Nothing else. (she is 6). The other is my fiance and the only places he goes is facebook and his hotmail account. He uses his account for the budget on the computer. That's it. He doesn't download anything. I don't download anything from an unknown source or a reputable source. I don't even open emails from people I don't know. I delete it right away before even looking at it. I scan all user accounts once a week, and have antivirus software on there (AVG free). I'm just confused as to how to fix this issue. I mean I could always just delete the user accounts but don't really want to. Is there a good free software that would help with this issue?
Thanks for help in advance!