Problems with XP and SCSI now but not previously

My system dual-boots between XP and Win7 because I have some legacy devices that I still use that won't work in WIn7. To dual-boot, I use the no-frills boot manager that came with Win7. One of the devices I use in XP is a SCSI scanner, and last time I checked, I could not locate SCSI drivers for my SCSI card with Win7, and M$ has made it pretty clear they aren't supporting SCSI anymore.

Unfortunately, my motherboard has one fewer PCI slots than I need, so what I have to do is unplug a firewire card and plug in the SCSI card when I want to boot the SCSI scanner. Now, in the past, there wasn't a problem doing this, but I tried it just now, and the system resets itself prior to loading the OS. So I've tried booting it to a last known good config with the SCSI card in place and it still resets. Then I tried loading it to safe mode, then rebooting, and still it didn't do any good.

So I pulled the SCSI card and re-installed the firewire card and turned the computer back on, and it started doing the same thing -- resetting itself before the OS booted up. So this time I elected to load the OS in Safe Mode, and choose a different last known good config. And that finally worked. I have XP back, but with my firewire card, and not the SCSI one. Hrm . . . maybe I should try choosing a set point from Safe Mode with the SCSI card installed.

Now, even though I didn't have to do this before, I'm wondering if I should disable the firewire card before removing it from the system so that when I restart the system it doesn't look for the firewire card. Think this might be the best way to proceed?

Also, one other thing I feel I should mention because it might be related somehow: after my system's most recent round of automatic updates for Win7, it did the same thing when I tried loading XP -- the system reset before XP loaded, but this problem disappeared and didn't come back after I chose the "last known good" setting again. Still, I mention this because this is a problem I never had until this last set of Win7 updates. Although I don't really see how there could be a relationship.

I have a peripherally related question as well. I can see the day come when I may just throw my hands up and say to heck with it, wipe the drive and reinstall XP. But that means I'll be reinstalling the copy I bought several years ago. And I guess I'm somewhat concerned that all the updates that M$ has released for XP may not be available any longer. So what does one do in this sort of instance? Are there stable archives around for all the updates to XP that one can still count on for the foreseeable future? Hey, I like Win7 a lot, but XP still does me just fine and, on my system at least, is the more stable of the two operating systems.