I am sure that machine will run Windows Xp, (you'll need at least 2 or 2.5 GB free on C: nothing else).....
I have a computer repairing shop and i have installed WinXp on these machines and they were working fine...
Compaq P2 with 300Mhz processor and 64 MB of RAM 6.4 GB HDD.
same brand with 400Mhz,64MB or 128 of RAm.
IBM and Dell's old P2 systems.
Dells P2s work just fine with 128MB RAM.
My own old AMD K6 500 Mhz with 64 MB was able to run WinMe, Win2000,and WinXpSP2.
it was a little slower on 64MB but an apgrade to 128MB of Ram helped me do jobs better.
So the above system should have no problem running win XP...
And win Xp is also easier to install ma friend.