Slow hard disk performance

hello, ive noticed lately that i have performance issues with my hard disk
the computer i am using was bought in 2005, but in 2011 i replaced the motherboard, the hard disk remained though, which makes it roughly 8 years old

i've tried fixing its (supposedly) bad sectors with an application, that only works when booted. it took about an hour or so for the program to scan and "fix" whatever there was to be fixed, but this didnt improve things

my new motherboard is good enough so i can play crysis 1 on lowest, i can use windows 7 with aero and so on...

my specifications are:

CPU: amd phenom II @ 3.1ghz (dual core)
RAM: 2gb ddr3
GFX: ati radeon hd 3300
HDD: 80gb (the one from 2005)

i dont really have funds to upgrade the hardware, so im curious if there is a way to improve it using some sort of an application
i have also tried installing various OSes: windows 8, windows 7 (both x64 and x86), windows xp (both x64 and x86), ubuntu linux... the first few days its working OK, but then when i install some software it gets a lot slower, also when i use uTorrent to download something, the hard disk is loaded on 100% which makes everything else so painfully slow, it almost makes me wanna kick the PC till it stops working  

so, please tell me is there any way to improve my hard disk's performance?