How to recognize a 'virus free file' ??

[Esa Anjum]

As my question describes my problem,I want to state that How can I be sure about the file I m downloading is perfect for my windows(w.r.t virus) & will not cause any problems..I have read about it on internet but....I still have some questions,which are as followed:
1.)What is the ideal size for a virus free file(e.g: GTA 4 rip is about 4.5GB ,is it safe??)
2.)Is downloading a pirated version of a game is always the best idea or buying it(pirated version only...not the original...remember it!)
3.)Does downloading a game online from any 'website' or with 'torrent' effects pc's performance w.r.t viruses & reg errors? & which one is the best of the two??
An Extra question.)I have win 8.1(genuine) & it has its(i.e: integrated) one & the only antivirus..will it help me to ensure about my safety?
NOTE : Plz answer my question with full concentration(answering in steps is better...).& plzz....plzz...plz dont give me links,just answer straight forwardly...
A request : If possible,give me links of the websites that share games WITHOUT any viruses(i.e: highly trusted webs..)
thankx in advance

 

[Wolfshadw]

Tom's Hardware does not support software piracy in any form. If you want to make sure your game files are virus free, purchase the game.

Wolfshadw
Moderator

 

[Darkbreeze]

If you avoid "pirated" versions in the first place, you won't have that issue. If you're downloading pirated material, you WILL get infections sooner or later. Don't download shady files and you'll greatly reduce your chances. Install Malwarebytes and keep your virus scanner definitions up to date.

Read this, and quite downloading illegal crap: http://www.tomshardware.com/forum/8263-63-simple-free-guide-removing-malware