I did a clean reinstall of FSX. When I reinstalled GSX it causes FSX to crash, it gives me a FSUIPC message saying the software has a conflict with FSX, then wether I choose continue anyways or disable FSUIPC FSX crashes to desktop immeaditely without giving any messages.
The problem doesn't have anything to do with GSX, which is entirely unrelated to FSUIPC, doesn't install, doesn't use, doesn't interact and it's not affected by FSUIPC in any way.
What you are probably looking at, is ANOTHER problem in your FSX installation, which is affecting BOTH GSX and FSUIPC.
Fact it "seems" to go away if you uninstall GSX, doesn't mean in any what that GSX is the cause. From your report, it's clear that both FSUIPC and GSX are equally victims of it, just in different ways.
If you are SURE you don't have an antivirus (not even Windows Defender
), it's likely a problem with your VC++ libraries, which are not updated or corrupted for some reason.
This thread indicates all the known possible issues and solutions:
http://www.fsdreamteam.com/forum/index.php/topic,7545.msg62899.html#msg62899