(help) laptop mobility to play games

Jul 17, 2016
i have an ASUS K42JC
Intel Core i3 M370 @2.40 GHz
2 GB (1.86 GB usable)
Win 7 32 bit
Nvidia Geforce 310M & Intel HD Graphics
300 GB HDD(100 GB On C:\ and 200 GB On D:\)
C:\ is 98% Filled
D:\ is 73% Filled

Physical Memory at the task manager stays at 1.26 GB ... idk why, and sometimes jumps to 1.56 GB.

i have friends , they play DotA 2 at 40-50 fps with their i3, 2gb ram, and intel hd graphics, on low graphic.
while my laptop can't even run DotA 2 on low graphic.
i play Battlefield 2 low graphic (yes, a 2005 battlefield 2) at 20-30 fps.(no mods)

i have latest driver for my Hardware, is it malware, or virus ?, checked and rechecked, none found, but every decent game i play, low-end game, can never run on 60 fps, the only game i play that run on 60 fps is don't starve.

is it my HDD space ?, idk what filled my C:\, i've never put any program there, i think it's the windows' files.

please help,i can't run any game properly, browser takes too long to start.
should i reset my laptop to factory state ?