XP re-install stuck in loop

System: Dell 8250 with XP Home

I had a problem with flakey XP hanging up etc. so was advised to re-install (previously I have been able to repair by booting from the Dell CD but this will no longer work) - is ther emaybe a counter on it? Going through Explorer I chose "setup" and then "update" (in the hope of doing less "damage" than a new installation). Unfortunately I did not unplug all devices hoping they would be detected and re-installed.

What has actually happened is that Setup has come across a USB driver it does not like and stops the installation with the major page long error message at the point of installing devices. This message is the one which talks of removing new hadware, changing video adaptors, deleting drivers and using F8 on start up to go into Safe Mode. It lists the USB driver as the stop reason. (The driver is ousbehci.sys if anyone knows what this relates to).

I recently installed a Sitecom combi card (2 USB + 2 Firewire ports) and a Belkin Bluetooth dongle and the problem may stem from here.

However, I am now stuck in a loop, I cannot get into safe mode because I get the message that Setup cannot run in Safe Mode. But I cannot do anything else. I cannot get back anyway to delete the driver because it has been picked up by Setup at the Preparation stage and there seems to be no way to get into DOS as I don't think it exists in XP.

So all I can do is run Setup until it closes the system and nothing else. ( I am not totally reckless as I have everything backed up and even tried to create Ghost boot disks in the past but have never been able to get this to work).

All my backups are useless until I can get the PC running again.

Can anyone help?