Installed otf fonts disappear after reboot

hello,
this is my first post here. (i've been reading this forum for sometime, good stuff)
i've stumbled upon this weird bug when i was trying to install .otf fonts...
fonts installing fine and applications can see/use them with no problem.
i can see fonts in 'fonts' list, everything is fine until i reboot windows.
when windows comes reboots neither apps nor fonts list is showing these fonts.
when i'm trying to install them again, i'm getting a message that they are already exist and if i want to overwrite them.
after reinstalling fonts, everything is fine again until another reboot.
i tried deleting them and reinstalling, changing permissions, etc., nothings seems to be working.
any ideas or suggestions are greatly appreciated! thnx!

i've tried 'right click/install', 'drag to control panel/fonts', 'copy to windows/fonts', 'font file/right click/unblock/install', etc...
the things is that fonts are installing and usable until i reboot windows... thx

sorry for replying to myself but i just wanted to share that i was able to fix this issue.

the problem was that font files were encrypted (green colored) and i'm guessing that after reboot they become locked and not available.

a quick right click and 'unchecked encryption' solved the problem.

i should have pointed out that the files were green color...

I had the same exact symptoms and the problem just turned out to be the filename extension. I had downloaded a few fonts that came in as unknown file types, and when I dragged them into the fonts folder, they installed fine as TrueType fonts and worked in all the programs. But then on reboot, they would disappear from the programs...but they were still showing up as TrueType fonts in the fonts folder. Every time I rebooted I would have to delete them from the fonts folder, them drag and drop the original files again to reinstall. Turns out the only problem was that the filename extension was missing from the original files - all I had to do was right click>rename the file and just add .TTF to the filename.

Of course this was a really simple thing that I overlooked, but just thought I'd post this in case it can help anyone else. Before doing anything else, make sure the font's file type extension is correct. Because without it, you'll be able to do a drag and drop install into the fonts folder, but then on reboot the files won't be recognized in your programs anymore. All other posts about this problem I saw online commented on editing the registry, logging on as administrator, too many fonts in your folder, etc. and my problem had nothing to do with any of those solutions

I can't find anything that says "encryption" to uncheck, but I'm having the same problem. Where can I find that box?

---Nevermind, I figured it out.
If anyone else has this problem, right click your font (in its folder before you install it), click "properties," "Advanced," and uncheck "Encrypt contents to secure data." That did it for me! Thanks!