Windows 7: No Audio OUTPUT Device is installed

I upgraded my computer to Windows 7 Ultimate 32bit and im having problems installing the Realtek sound driver that's compatable with my computer. Every time i install it it says i dont have acces to memory location. I tried every solution on the internet but nothing worked. Please help me, im desperate!

While you are waiting any chance you can give us your system specs, and what driver you are attempting to install (link to it please)

Realtek - here's the driver and by far as i know i have a intel pentium 4 , 3.00 Ghz and a ASUS motherboard (i dont know what model)

Uninstall the driver and check the delete the driver software box from the device manager and reboot.
Windows should install the generic driver.
Try installing the Realtek software.
If successful and you still have no sound, unplug the speaker cable.
Plug in the speaker cable and wait for the jack detection pop-up.
Press OK.
Hopefully you should have sound.

I uninstalled the driver and rebooted but a message pop's up : The device was not installed properly.

Uninstall Realtek from Programs and Features in Control Panel.