When you reinstalled, did you also restore your old data?  you may have the malware in your profile directory and if you just copy your whole folder from \Users, you will only continue to reinfect yourself.  Also some tools to use to check some things out, Microsoft Sysinternals has a number of free tools available.  A good one to use is Process Monitor, which logs all active processes on the system.  It also logs the network activity that a process us causing.

Another app in the Sysinternals suite is Rootkit revealer, you mean want to run that and see if you have a rootkit.  Make sure AV is installed and updated, as well as something like MalwareBytes.  Then reboot the device into Safemode, no networking.  Run full scans using both AV and Malwarebytes.  Another tool to try is the free tool from McAfee call Stinger.  This is a scanner that runs standalone and is typically updated regularly, so no need to run an update after downloading.

You also may want to re-evaluate your internet behavior.  If you are a torrent fan, you may have picked something up there.  I would recommend in the future to install something like Virtual Box and build a nifty linux Virtual machine.  Then run your internet surfing from there.

Good luck!