David,
The CallManager installation disks will only install on Cisco MCS boxes - the re-badged Compaqs. 3.0(8) was the first version that was also available for Compaq and IBM branded servers - but your disk set may not have the correct files for these.
For the server specifications look at:
http://www.cisco.com/go/swonly
Be aware that the currently shipping MCS servers from Cisco are not supported by the 3.0(8) release due to hardware changes.
Hope this helps,
Justin