Won't detect network...

I have a cable internet connection with a wireless router, and every now and then when I turn on my laptop (inspiron 5150 running windows xp pro) it refuses to acknowledge the presence of an internet connection (wireless and wired alike). My roommate's laptop (inspiron 1100 with win xp pro) never has this problem, so to my knowledge the connection can't be the cause. It never goes out when the computer is already running, the problem only happens if I reboot (like when I wake up after turning it off the night before). I've tried unplugging the modem/router and things like that anyway, but my laptop doesn't show any progress.

My laptop is a Dell, so I have some sort of utility that monitors wireless signals in the area. When I am having this problem the utility will detect that the network is there and monitor the signal strength but it thinks that it is not something I can connect to (it displays that no wireless connection is available). Also, the utility will sometops stop saying "no connection available" and display that I am connected to a 0Mps connection with gargage characters for a name. The windows network connections, however, claims that no network is there at all (no matter what the utility says, no connection/garbage). I can refresh the list of networks all day and it comes up empty.

I called Dell about it once and they weren't too interested in the details, they just said to do a system restore (which happened to work that time). Today when I ran into this problem a system restore did not work, however the problem did eventually go away randomly... one of the times I restarted it just magically connected to the wireless network. I didn't change anything before restarting that time. The next time I restarted, however, I had the problem problem. After restarting a few more times it finally picked up the connection again.

Another detail... when it is not detecting the network I can't disable or edit the network card in any way. If I try to disable it or roll back the driver it just freezes. Everything runs fine but that process stops responding.

I've checked for ad/spyware, viruses, general programs that I can think of that might conflict in some way, but I've come up with nothing. Granted I'm not so gifted in networking, I'm obviously missing something.