When working with our core image for Windows 7 I found that restoring an image that has not been syspreped results in a boot error. You can go through the windows repair and let it try to "fix" the issue. Or you can simply use bcdedit to "reset" to boot information. I never had this problem with Windows Vista Images, so it seems to be the new boot manager with Windows 7 that cause this issue. It's probably a good thing to keep unauthorized (and un-sysprepped) images off of your network.

1   ) Restore the Windows 7 image onto the computer
2   ) Boot with the latest version of your Altiris bootdisk.
3   ) Run these commands:
3a ) bcdedit /set {default} device partition=c:
3b ) bcdedit /set {default} osdevice partition=c:
3c ) bcdedit /set {bootmgr} device partition=c: