I have been thrilled with my Arduino board and software for a year now. I recently upgraded to the 1.6 Windows 8 Installation. Somehow I have destroyed, moved or lost the COM5 driver. Windows cannot find it, even with online search. I have uninstalled 1.6 and reinstalled 1.0.5 without effect.
I had two installations of Arduino, one in programfiles(x86) and another in a library file with all my sketches. Neither Arduino.EXE will find COM4 or COM5 the two usual suspects when cabled to the board.
When the IDE is opened the Tools>Serial Port tab is grayed out. Device Manager has an apostrophe next to COM5 only when the board is connected.
I haven't found a forum entry with this problem discussed.