Lostgallifreyan wrote in
:

REGEDIT4


Right after that, before the rest of the template, it's wise to put this:

[-HKEY_LOCAL_MACHINE\SOFTWARE\CLASSES\.asc]
[-HKEY_LOCAL_MACHINE\SOFTWARE\CLASSES\LTspice]

Note the dashes inside the key path brackets. Those mean DELETE the keys,
which means when the template puts back your linkage, you can be totally sure
that no pollution was left behind by whatever program stole the association.