Sounds like you have some issues here. (No pun intended.)
You may need to do a re-install of your OS. Perhaps not though.
Drivers should always be installed in this order:
1. Chipset Driver
2. Graphics Driver
3. Network Drivers
4. Sound Driver
5. Modem Driver
6. All remaining drivers.
Store the drivers on an external hard drive, thumb drive or a CD-RW disc.
Do you have the latest BIOS Firmware update?
For the latest nForce Chipset driver go to:
http://www.nvidia.com/object/nforce_...bit_15.49.html
For the latest GeForce graphics driver go to:
http://www.nvidia.com/object/noteboo...5.62_whql.html
The rest you can get from the respective websites.
I hope this helps.