It probably didn't copy the boot sector or the MBR.
You'll probably need to get the hard drive to another computer, set it so it is the partition on it is active, and then put a boot sector on it.
Here are some links that may...
A few questions:
1. Did you format the drive to be bootable?
2. Did you set the partition to be active?
3. Did you just copy the files over to drive (like through Explorer), or did you do something like image the old drive to the...
2K Pro may be a better solution - it would let you test more scenarios than XP Home. Especially with the user permissions and rights scenarios.
However, with the security push, you might have to stick with XP Home or do dual booting.
Fire up BearShare, then fire up a Command Prompt. Wait for BearShare to connect.
Then in the Command Prompt, type netstat and see if it makes any connections (they should say ESTABLISHED). If there aren't any, then try explicitly...