Windows 7 - Asking :SOUND DRIVER High Definition Audio Device Driver

im using now a sound driver default "High Definition Audio Device"Driver
do i need to uninstall it first before changing to realtek sound drivers??
and how do i uninstall it in safest way??and was there an option to undo if something goes wrong??

im using windows 7 ultimate 32bit. ..

That is the default Windows audio driver, and I don't think it can be uninstalled. Best is to not worry about it and just install the Realtek driver.

Uninstall the Realtek driver or do a system restore to before you installed it.