Disturbing message box while opening folders

[md]

When i try to open folders a message box displays warning me that my system is in a critical situation and dangerous viruses are trying to destroy files in c:windows...also a my firefox browser pops out in which a new tab appears..it asks permission to download a file called ie-av.exe....
please help me out

[DavidR]

What ever you do don't download anything, this is scum/scamware trying to either have you install something which may well infect your system. Or they will be after payment to fix non-existent problems.

If you haven't already got this software (freeware), download, install, update and run it, preferably in safe mode and report the findings (it should product a log file).

SUPERantispyware On-Demand only in free version. MalwareBytes Anti-Malware freeware version http://www.softpedia.com/get/Antivirus/Malwarebytes-Anti-Malware.shtml or try this tool, RogueRemover, available here http://www.malwarebytes.org/rogueremover.php from the same company.