Not sure if this will be universal or not but it looks like quite a few XP users are having the same problem after installing the new version of alcohol. All is well until reboot after first use. Then you can't boot into windows. You have to boot into safe mode and hit escape to cancel loading xmasbus.sys and then uninstall alcohol, or disable xmasbus and xmasscsi in the recovery console.
These mount the virtual drive so if you disable them you can still use the other parts of alchol.
jb