I think you are referring to a PATA/IDE 320 GB HDD.
It will most surely work.
Also, if ur friend is using Win2k or WinXP or greater OS, it is sure to work.
But if its a SATA HDD, it won't work. You would need a PCI to SATA adapter or HDD enclosure (thru USB) for making it work.
Actually i have a 160gb disk as slave, i was using only 120gb till now. But today through the windows disk management, i have formatted the remaining 30gb and windows recognises! But you need to install Intel Application Accelerator.
So i guess, 350gb should not be a problem.
I had first formatted the 160gb from dos, so the whole 160gb was not detected. But windows will recognize your whole disk, just don't forget to install IAA.