.Net COM-interop DLL registration

I've been working on a project that has sort of a thin service layer that's exposed to some legacy COM-clients. When developing on my local machine I let VS.Net take care of the registration. For stage and production I produced, what I thought was, a really simple solution with a .bat script that simply runs RegAsm. I had to play around with the arguments untill I found out that /codebase was the switch that worked best. This worked very well on one machine and not at all on another etc etc.

After a terrible attempt to put the code in production yesterday I got frustrated enough to throw the .bat file approach out the window and produced a MSI installer for the solution. No more problems. No more .bat script. No more registration problems. Next, next, finish. Love. Peace. Harmony.

And then the frustrated question, why didn't I do that in the first place?