XAMPP completely blocked?

Is it possible that the presence of the Comodo free firewall (no other Comodo software installed) could have completely blocked operation of XAMPP on Windows7? I have had the latter running for years, installed Comodo, several weeks later (other software installed in the meantime; I am trying to narrow down the possible cause) I got only error 500 Internal Server Error.

Uninstalled XAMPP, tried to reinstall its versions 1.8.2, 1.8.3, portable or not, highest administrator status, correct Microsoft C++ redistributable package, firewall turned off completely, no active anti-virus spyware.

Iit will not install, with various error messages having to do with permissions, suggestions that the redistributable is not there, and that the executable is damaged.

Does this sound familiar to anyone? Thanks a lot.

Is it possible that the presence of the Comodo free firewall (no other Comodo software installed) could have completely blocked operation of XAMPP and [i]Microsoft C++ redistributable package[/i] on Windows7?
I hope not Look at the pictures I uploaded in this post and check those locations where the red arrows are It'll be called sshot-1.png sshot-2.png sshot-3.png sshot-4.png

as for

error messages having to do with permissions,
Thats kind of weird Install "take owneship that I uploaded here

In windows explorer find where xampp is located. now right on the xampp folder and click on “take ownership”. If comodo gives any pops, click allow and remember answer
When done, Try opening the file again. Do you still have this error. If you do reinstall everything and take ownership of everything then open it

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