Just got problem, when tried to update synergy on my 64bit Win7 box. Seemed that installation went well, but when synergy started one line showed:
ERROR: invalid shell library, use a newer synwinxt.dll
Tried reinstall, and clicked on “Show details” on installer window. There was an interesting line, that told “synwinxt.dll already existed” (or something similar). So, I did uninstall, and whoa – there still was existing c:\Program Files\Synergy\synwinxt.dll” file. Tried to delete, but no success – window$ said, this file was used by explorer.
* Uninstall synergy
* restart windows
* delete c:\Program Files\Synergy
* install synergy