Vista - nvidia vga driver problems acer aspire 5520

Hi people.I have a little vga driver problem on my new acer aspire 5520.I recently installed Windows vista ultimate 32 bit on it and everything works just fine exept the video card drivers.I tried using all sorts of drivers for vista 32bit including the latest ones but the problems don't disappear.My video card is Nvidia 8600gs and every thime I try to install drivers for it the setup says that it doesnt find drivers for my hardware or thatthe operation system i use is not vista 32bit.Finally I decided to bypass this problem by installing the drivers with device manager and it seemed like I had succeeded,they did install.But they worked terrible.The log on and log off animations became so ugly and any thime i even tried to run "Minesweeper" or open a picture this weird and bad blue screen(the one appearing when your hard disk stops working) appeares that said"If this is the first time you see this window...bla,bla"and then the laptop restarted.I tried to solve the problem myself with no result(exept i went pretty mad).Please help me.

Do you have SP1 installed as I notice on Acers site they have vga drivers for with and without sp1.

Acer Europe - Service & Support, Drivers & Utilities, Downloads, Notebook, Aspire 5520