Vista - WIFI driver re-set problem

I supposed this is linked in to various posts including the 'Wireless
Association due to an unkown error' query.

Got an ADVENT 7109 laptop wit a REALTEK WLAN wifi driver built in. Wifi
worked wonderfully under XP.

Installed Vista Ultimate (boy is that exppensive)

Suddenly NO WIFI....cam up with the above error. Downloaded REALTEK driver
update....would not install driver. So finally went back and re-installed XP
driver! WORKED A TREAT yeah! Instant wifi.

Problem solved?? NOT !!!!!!!!!!!!

Every time.....YES EVERY TIME I reboot I have to re-install the old driver
to get the wifi to work again. This is annoyng and pointless.

How do I stop Vista Ultimate doing what ever it is doing and re-installing a
'more up to date' driver that DOESN't work at reboot so I don't keep having
to do it every time.

PLEASE HELP!!