after beating my brains out , I found out how to add win7 to a double boot with win xp and pclos.
So, if anyone else is in the same sitch...this is how you do it:
1. use gparted to create a partition for win7, make it bootable.
2. hide win xp and remove the boot flag.
3. install win7 into your prepared partition
4. unhide win xp.
5. install pclos to its own partition(s) ( mine is on a separate drive)
6. setup grub to boot winxp and win7 from their own partitions. you can actually assign them in the pclos installer. Mine looks like this:
title Windows 7 RC1
title Windows XP Home SP3
8. go back into pclos under root and change the order if you want.
Works great! Each OS boots directly to its own logon page.