Registry mechanic....
AVG anti virus - payed edition .... all though not paid - naughty me

I did have spyware doctor but didn't update correctly so went and got the old spybot S&D
My pc specs are not bad.....
Pentium D 3.2GHz
2GB RAM
150GB SATA harddrive
32bit Vista
8600 GT
5.0 score on vista.....
I bought my computer off a good friend and he had no what soever problems when he had it and i mean none.... however as soon as i have it....... everything goes wrong first it kept freezing and saying 'security options failed' fixed that i think........ however now it crashes and says a different message...
It crashes when just on the internet or talking on msn messenger it also crashes when playing games not all the time but 25%.
'The instruction at 0x75635000a refenced memory at 0x56415c68. the required data was not placed into memory because of an I/O error status of 0xc000009d.
I know the numbers change on each application that was just an example.... when it does this i terminate the programs and then im left with my wallpaper and rocketdock and then i can move the mouse freely etc just nothing will not work and my explorer goes away....
After this has finished i have to cold boot it and almost everytiem it doesnt read a harddrive and tells me to sort boot device out which is no problem most startups..... so i coldboot again and most of the time it gets to wear it should be loading vista but just stays on a black screen...... so i reboot AGAIN........ and this time its 50/50 it either loads properly or it stays on vista loading screen forever.....
I dont know whats wrong but i scan my pc alll the time and dont go on nothing i shouldn't only thing i can see wrong is me playing copied games from my friend but everyone nowadays does this...
Please help
