You know PickaxeFairy
It is obvious that something is wrong with your setup, as I said before my system is older than yours and I have used both Windows XP Home and Windows XP Pro and I have never experienced the problems you seem to be going through. Even when I used the USB V1.1 ports that came with my PC.
Again, I have five external USB drives, three made by Lacie and the other two by Gericom. All of them are plugged into USB2.0 ports, provided by 2 x 4 port USB2.0 PCI cards (similar to one displayed here:
dabs.com - Best Value 4 PORT USB2 PCI CARD (US102)), and each external has it's own power supply unit, i.e. all draw their own electricity from my lead, (similar to this:
Currys partmaster.co.uk - Avix 13A 6 Gang Surge Protection Extension Lead With Telephone Socket) and so does not use power from my PC.
So if your externals have their own power units then they should not slow your PC down or have slow start up problems.
I would suggest that that something is wrong and you should have your setup examined.
UK Bob