Okay, if that's the way you want to go. Be aware that the old MSI code is gone though, so rebuilding it will not be trivial. Though if you do, there are a few people who would find it more convenient, so you may be able to enlist help maintaining it (we didn't get any offers of help, just requests for free work, so you may not get it either...)

If you're having trouble with a range of installers, there's a process you can run to reset your security policy, which is what I'd suggest doing. I'd have to find the details for you, but it basically resets permissions on everything. Doesn't delete any files, but may help with this problem. Let me know if you'd like me to find the details (requires Windows Pro IIRC, at least pre-Win 10).