I have a DELL 4600 running Windows XP SP2. I was having problems with IE 7 displaying certain web sites that would display on another system running IE 6 so I decided to reinstall IE 7. After the IE 7 reinstalled and it prompted me to reboot, the system seemed to hang at the Windows XP screen where the line across the screen moves during initial start up. I performed a cold shutdown by holding the power button until the system shut down and then when I powered up it prompted me to go into safe mode. I was able to go into safe mode with networking.
During the intitial startup an error flashed across the screen stating "Error allocating IRQ for PCI device".
After going into Safe Mode, I selected control panel - system- hardware-device manager -other devices - SCSI Controller and discovered that this device is configured properly. I tried to delete this device driver and then let plug and play work its magic but after rebooting Windows still hangs.