Most of the problems under discussion appeared to be involved with earlier drivers and software remaining on the system and causing conflicts which prevent the new adapter working. I followed your references up, but they didn't take me much further.
The little blue LED on the adapter doesn't light at all, yet when I switch back to my b/g Sitecm adapter it works perfectly in the same USB socket. So far, every time I run the installer, the software installs, I am asked to insert the adapter, the Windows messages 'Found new hardware' and 'Your new hardware installed successfully' appear, the installer screen switches to 'Detecting adapter' and just hangs. I have been uninstalling the software between each installation attempt. I have since been in contact with Netgear's on-line assistance and they have made various suggestions :- disable A/V and firewall, reduce the amount of RAM (?), use the latest driver - but it still hangs at the 'Detecting adapter' screen. I installed on an old laptop running XP SP3 and it went straight in off the CD and connected flawlessly to my router and the internet - so the adapter works. Trouble shooting on the Netgear site suggested trying installing it on another computer. I then got the newest driver from the Netgear web-site, same result. I took it back to Maplins who exchanged it without question for another, and tried again, with the same result. It was still detecting the adapter when I got back 45 minutes later ! I uninstalled the software and tried again, with exactly the same result, except that this time I left it while I went down to the local supermarket for the shopping. It then came up with a sub-screen saying 'Detecting adapter. I switched off my computer, unplugged my b/g Sitecom adapter, re-booted and put the CD in and followed the on-screen instructions upto the point where I was told to insert the adapter. I picked this adapter, from my local Maplins, because it specifically listed Win 7 on the box. My ISP recently gave me a new 802.11 g/n router, my wife's laptop is g/n capable, so to take full advantage of the n capability I bought a Netgear N150 USB adapter ( Model WNA 1100 )to use with my desktop, which comes with an installation CD.
Computer :- 64 bit Win 7 SP1, fully patched, ASUS M4N68T-M motherboard, AMD Athlon 2 x2 250 3.0GHz processor, 4 Gb RAM