messed up browser?!

Try using Windows Defender Offline to see what it comes up with. This is a bootable AV disk. Burn it, insert it & restart the PC, let it scan.

What is Windows Defender Offline?

Another option:

Norton Power Eraser

Norton Power Eraser | Free Tool |Easily remove scamware that traditional virus scanning can

Because Norton Power Eraser uses aggressive methods to detect threats, there is a risk that it can select some legitimate programs for removal. You should use this tool very carefully. If you accidently remove a legitimate program, you can run Norton Power Eraser to review past repair sessions and undo them.

Please try what Borg 386 has suggested. If Opaserv Removal Tool did not even detect it then it is perhaps not there. Which Rootkit Removal Software out of the five did you run?

If you are going to reinstall W 7 then do it after deleting and recreating the concerned partitions (System Reserved and C). I only hope that your computer is not infected with a BIOS or a hardware virus because the virus seems to be coming back after a clean install.

Run Windows Offline Defender, this is a scanner that will run at boot up and may reveal some hidden items.

One rootkit scanner that wasn't listed in the list was Kasperskys TDSSKiller.

Anti-rootkit utility TDSSKiller

Before doing a clean install, you might want to consider using something like DBan to wipe the entire drive, as some viruses are known to survive a re-install.

About DBAN | Darik's Boot And Nuke

If it comes back after that, consider this possibility:

Are you introducing files back to the system that haven't been scanned? If you backed up your personal files while your PC was infected, there's a good chance you may have transferred the virus to the backup medium, hence the reason it keeps showing up once you re-introduce the files to the clean system. Also, your FD may be infected which loads the virus when you plug it into your PC.

VirusTotal will scan files up to 32MB with several AV's. Consider scanning some of your saved files there:

https://www.virustotal.com/

Catching BIOS and Hardware Viruses is very rare but not impossible. If you want I can show you a few sites to learn about them but you can find all about them yourself by googling.

Here are two sites for BIOS and Hardware Viruses to begin with:

BIOS - https://www.google.co.in/#hl=en&outp...w=1024&bih=672

Hardware - https://www.google.co.in/#hl=en&gs_n...w=1024&bih=672

You mean that you are unable to access the sites you want even with IE/Chrome/Opera.

It sounds like you have a browser re-direct, see this thread, Post #5, and follow the directions

Detected DNS cache poisoning attack.

Have you ran Windows Offline Defender yet?