I'd need to do a little more research into this, maybe search engines have become worse or this is such an uncommon issue it's not too known.
Initially I did get some tips that may help digging through Steam's support, though, I'll just list them in no particular order.
* Check any third party antivirus software, they may be interfering the link between Steam and Windows
* Reinstall Steam in the same download location
* Wipe the download cache for Steam
* Repair the Library folder (this is where you install games, you can view this in the Steam settings, you can also try installing it to a different Library folder)
* Delete everything in the Steam folder except for: steam.exe, SteamApps, and Userdata folders, and then run steam.exe inside the folder.
Hopefully one of these helps.