re-install xp home

[scodacious]

I am attempting to fix a friend machine that the oem os is windows xp home edition. I have a case where the inital os installed was xp home but was upgraded to xp pro but have no recovery disk for xp pro. I do have the original recovery disk for xp home. When I attemtp to use the xp home recovery disk I receive a message that it cannot find /i386/asms in order to go further. When I select my os the screen show xp home but when the machine starts it is xp pro. Any ideas on how to do a complete install of home edition with recovery disk. I do not have access to an actual xp home disk. Any help is appreciated.
My only other option is to purchase a new hard drive but can I do an install of xp home from the oem system recovery cd. this is an emachine if that makes any difference.