I have 2 Dell D600 laptops. Both were originally loaded with Windows XP, and both were updated to Windows 7 - prior to my ownership. I purchased both just to have some machines to carry here and there with access to WiFi - no heavy work or gaming or anything like that.
The first, I can connect and use the WiFi, but when I shut down the machine, I must do a hard shut down, as it gets stuck in a loop of restarting if I try the correct way to shut down. This only happen when I have fired up the WiFi. Otherwise it shuts down properly. I tried change the WiFi adaptor, but then the machine wouldn't start at all. I had to put the old adapter in, just to get it to fire up.
Now the second machine... It came with a new WiFi adaptor installed. It's tremendously slow, so I have cleaning it out - getting rid of unwanted programs and cleaned the registry etc. After this house cleaning I shut it down. When I went to restart it - zip. On a whim, I disconnected the WiFi card, and sure enough the machine fired up. I shut it down properly, reconnected the wifi, and it fired up OK.
Any idea what the relationship with these wifi adaptors and why they can cause a computer not to start at all.
While I was writing this I was re-starting the second machine - which I bought off eBay. Darned seller loaded an illegal copy of Windows 7 on it - so I guess I'll be taking this one back to XP one way or another. Errr...