This problem just occurred today when I tried to connect to T-Mobile Hot Spot and I never had problem connecting to a wireless access before. I tried to disable the wireless access from safe mode and restored to a previous restore point but the blue screen still occurred even in the safe mode. Finally after leaving it for a while I could get the windows started. I had disabled the wireless and it works fine now when I used LAN connection so I assume the problem must be from the wireless adapter. Computer spec: dell inspiron 600m, win XP Pro, ATI mobility radeon 9000, 1.4 GB pentium M, 256 MB intel PRO Wireless LAN 2100 3A Mini PCI adapter. I checked Dell support site and it seemed dell had discontinued this wireless. I have updated the latest driver and the blue screen still happened when I enable wireless connection. Is there any other issues that might cause this blue screen problem?

Usually a driver problem. Try an earlier version of the driver.
A blue screen can result from any hardware or software problem, or an infestation... But Driver IRQ not Less or Equal... is nearly always a failed driver, or a hardware problem related to it.