Laptop suddenly running slowly/laggy/choppy

[Boldo]

So, the other day my laptop started running really slowly. It might be because i installed a few games (torrented) so i installed AVG , did a thorough scan , nothing was found, so i formated the laptop, reinstalled win7, deleted the games, but still it runs really slow. It didn't do that before.
Not sure what to make of it. Any ideas?
Also hard drive is fine according to scans, got the correct drivers from the the dell webiste with its updater
I5-2,4GHz
8GB RAM

 

[Lutfij]

1| Can you pass on the make and model of the laptop? An SKU would help.
2| You downloaded pirated versions of the games off torrent?
3| Is the installer for your OS genuine or is that pirated as well?

 

[Boldo]

1| Can you pass on the make and model of the laptop? An SKU would help.
2| You downloaded pirated versions of the games off torrent?
3| Is the installer for your OS genuine or is that pirated as well?

1. Its an inspiron n411z.
2. yes
3. yes
It used to work okay but after installing games it just became choppy, and formating (using iso) doesnt help