[SOLVED] Windows wont let me enable wifi adaptor

I've just installed a wireless PCI adaptor (Tenda W322P) in my PC but I can't 'enable' it - every time I double click it starts to enable then stops and leaves it disabled.

The system is definitely seeing it as it's listed in Device Manager, and if I bring up Network Connections (using ncpa.cpl) it's listed and shown as disabled. Why would windows stop it from being enabled??

I've tried downloading new drivers from the manufacturers site in case the drivers on the disk were old - no difference. I uninstalled it and removed the drivers and then re-booted so windows would use it's own drivers - no difference.

It seems the system has a problem with it, but surely ONE of the drivers would work if it was a driver problem?

UPDATE:

I read elsewhere that anti-virus progs can interfere with driver installation, so tried this:

- Disabled AVG 2011, then uninstalled the wifi card
- rebooted into 'safe' mode (with networking), installed the wifi card and let windows supply the driver
- it works!
- rebooted into 'normal' mode and it still works - BUT THE PC HAS SLOWED TO A CRAWL
- by that I mean it takes between 40-80- seconds to execute every key press or mouse click

Re-did all the above twice using the latest drivers from Tenda's website and Ralinks website - same problem with each.

So, this leaves me thinking it's nothing to do with the Tenda card or it's drivers (these are very common cards and most people on the net post good things about them) but is a Windows 7 problem (well, no suprise there.....) compounded by AVG not allowing driver installation.

I'm baffled - any thoughts?

I see it uses a Ralink chipset, perhaps you might try using the latest Ralink drivers from 5-23-2011

Here's a link to the download page: http://www.ralinktech.com/support.php?s=1

I tried the Ralink driver - the latest - but just the same. The fact that all the drivers make it behave the same way makes me think it's some problem with Windows.

SOLVED IT.

I uninstalled AVG, then ran avgremover to strip out all the cr#p it left behind. (Then I found remnants of Kaspersky anti-virus installation from 2 years ago so used kavremover to get rid of that too.)

Then uninstalled wifi card and it's drivers, and rebooted into safe mode. Installed latest card drivers and it worked fine.

Re-booted into normal mode - still working fine - and then installed Avira Free version, which doesn't seem to have any problems with it as it's all working.

So, it looks like it was down to AVG having issues with driver installation, or at least THESE drivers as I've not experienced this before.

Good! You're problem is solved! But, now that you know AVG is a POS, you may as well install Avast or MSE.