[Aerosol]

I uninstall it. I run Malwarebytes and CCleaner. I don't see it for a few hours. Then I'll be browsing a page and hearing random ads, seeing little boxes with the words "ads not by this site" on them, and random words being used as hyperlinks to pop-up ads. It goes by the name of ScorpionSaver currently, though I've seen it called other things on this computer before.

How is it installing itself and how can I be rid of it once and for all??

[TmEE]

From another installation, manually scrubbing it out. Hiren's Boot CD or other OS in a multiboot system are good choices.

[Overlord]

Failing that, backup your shit, and reformat/reinstall. Gets a clean and fast Windows install out of it, too.

[Aerosol]

I don't think a reformat/reinstall is an option. I don't own this computer. It's rented.

[Vangar]

You could try running combofix from bleeping computer, if it is listed as malware in that software it should remove it. It's also free.

[TmEE]

IF combofix runs... when it does it does wonders !

[Uberham]

do the malwarebytes scan in safe mode.

Also, get adblock plus and noscript if you're using firefox.

also, try using Spybot Search and Destroy, and using the "immunise" tool.