1. Click start, run, type in "regedit", and press enter
2. Click on the "+" for HKEY_LOCAL_MACHINE
3. Keep clicking on the "+" for: Software, Microsoft, Windows, CurrentVersion, App Paths
4. Find "HalAsst.exe" and left click on it once to highlight it
5. Right-click on "HalAsst.exe" to bring up a pop-up menu
6. Select delete to remove "HalAsst.exe"
7. Reinstall Hal normally, it will now allow you to
Be very certain you are only deleting "HalAsst.exe" and nothing else. This is where Windows stores all its settings so you may irreparably harm Windows if you change or delete a setting accidentally.
I recommend always using the uninstall function before removing Hal from your computer to prevent this from occurring again in the future. Enjoy Hal and let me know if you have any more problems.