[Best Anti-virus/malware settings for an OLD PC]

I'm sorry but I failed to add - Please suggest a better alternative or the best security setting for an OLD pc like this.

[Best Anti-virus/malware settings for an OLD PC]

Hi folks,

 

I am using an old P4 (3 GHz /512 Ram) dedicated for downloads (specially torrents) 

I had installed AVIRA free edition - but now the rig is really terribly slow so much so that browsing is a pain.

I was thinking of getting rid of AVIRA. 

I have Malwarebytes already installed on it.

Would a combination of Malwarebytes and the KAspersky free virus scanner tool  that scans only on demand - no real time protection (http://www.kaspersky.com/security-scan) be enough as long as i have a pop up blocker and browse safely?

 

My basic requirement is to ensure that the old p4 is virus free since I transfer files from it to my Laptop (which  does have Kaspersky AV installed on it)