Old laptop sys + security questions

[Ouroboros]

Hello, 

 

first of all sorry if this thread  doesnt belong in this forum section. 

And i know im a little bit paranoid but... well, it is what it is.

 

So i have this old laptop, and generally speaking i would be realy, realy surprised if it didnt have a viruses and other ugly things since it was used to download random things from even more random sources...

 

My question:

 

Could i solve this by just reinstalling W7? Or should i do something else? Basicly i wanna clean, virus-free pc, as easly as possible.

 

Also what would you suggest W7 + free AV or just Ubuntu (if so, i can only use wubi and then upgrade)?

[qwertywarrior]

a reinstall will remove all the viruses

unless u have one of those viruses that embeds in the Bios  which i DOUBT so dont worry about that

if ur super paranoid just reflash the bios with a new one

 

reinstall w7 and install free avast AV