downloading

[Sixxth]

SO, let me sum up.
-Launcher wont Open, your machine says it was a virus and deleted it
-You have no anti-virus software on your computer (seriously?...)
-Maybe its windows explorer infected with malware, but cant upgrade because...malware? who knows

Seems to me your next step is get an anti-virus and scan your machine. Lots of free scanners available. (Avast is one that some friends use and like, also Malwarebytes anti malware is popular).
I would recommend Hiren's boot CD, but it takes some PC chops and I dont know your skill level.

Alternative - Get a new machine, install some antivirus software, start EMU install all over.

Profit.