OK, so this happens with my brand new CS 767 and also on trying to run the 4.6 upgrade for my CS 757 (which was already installed, I removed it to fault-find and it now won't install back in at all). Essentially, I run the installer and it goes through the activation point to the point where you can select the directory and can press "install." Except, the install button is gray, non-clickable and if I try and change the directory it still remains gray.I have reinstalled FSX with Acceleration. I have run the free FSX registry tool from Flight1. I have used CCleaner to clean out any reference of captainsim to try and allow a fresh install to occur. Stumped, I then searched Google and found nothing on this issue except a thread at sim-outhouse that stated that someone over at the REX forums had found a fix. FUrther research showed that REX changed forum software since then and the thread is at the bottom of the internet ocean. So, moving towards asking CS for help, I then searched Captainsim's knowledgebase to make sure I wasn't burdening them unnecessarily and I found a vague article that tells me I must not have enough HDD space to install, or to try a complete FSX reinstall. Having over 300GB of free space, I knew it wasn't that so I did a reinstall. So after doing everything it says to do and with the issue still occurring, I open a support ticket with CS and they reply after 2 days with a cookie cutter answer to go and check the knowledgebase article I'd already found (and had stated in the ticket that I had followed it already and the issue still occurred). Now they essentially refuse to help, but of course they gladly took my money. I could get a refund, but what's the point in that? I want this aircraft that I've paid for to work like the PMDG, IRIS, Aerosoft, ORBX, and many other addons I have paid good money for. So if anyone knows what might be the cause, or can remember the fix on the REX forum, I certainly appreciate any help you have to offer.

The only thing I can do to get the install button grayed-out is to have the wrong folder name in the installation path text box. Have you tried getting new download links using a new installer?The best thing for this would be to ask on the Captain Sim Forums. There are some people there who could definitely help (they're probably on avsim, too, but you're more likely to get noticed on Captain Sim). Also, while Captain Sim's customer support system is pretty poor, on the forums you can speak nearly directly with them (screen names Captain Sim and Captain Sim 2).

Yes, tried a new installer for the 767, not the 757. Upon changing the path, nothing happens for me unfortunately. I now believe it to be something related to the registry, just a hunch.

That's usually the problem on this sort of thing. I'll ask somebody on the CS forums and see if they know how to fix this.

OK, thanks Bram.