I made the mistake of installing a FSUPIC derivative mod (MaldAir VA) onto FSX, when I had FSX-SE also installed.
Un-installed all, reinstalled, edited registry keys as per this Steam forum post, downloaded fresh MaldAir Installer, installed, tried to run any applications results in the following error:
"Component 'MSINET.OCX' or one of its dependencies not correctly registered: a file is missing or invalid"
Attempted to extract msinet.ocx from the downloaded files, to windows/system32 and no success. Unsure how to resolve.