One of the two RAM DIMM sticks in my main PC went bad last week. So, I had to unplug the cables from the back, take the case cover off, replace the bad DIMM (lucky to have guessed on the first try which of the two DIMMs was bad), replace the cover, and plug all the cables back in. Simple, right? One would think so. But, not really.
My Bluetooth USB dongle is on a USB hub. When I plugged the hub and other USB cables back in, I didn’t plug them back in to the same USB ports they were in before I took the PC’s case cover off. After I turned on the now repaired PC, I tried to Sync my Windows Mobile smartphone over Bluetooth. Didn’t work. When, I checked ActiveSync, it showed grayed out options. A bit of digging around revealed that the pseudo COM port Windows XP assigned to the Bluetooth dongle had jumped from COM4 to COM6. A bit of fiddling around fixed this and got things working as expected.
So, if you need to pull cables from your PC, be sure to note which physical port the Bluetooth dongle is assigned to. FYI: This is an issue for the USB sync cable too. Although it does not suffer from the jumping pseudo COM port issue, Windows will not recognize your Windows Mobile device hardware and will have to re-recognize it. This should not require any intervention on your part. But, it does take a bit of time and may be anxiety causing the first time you see this. This has been like this for years. So, I don’t expect it to change anything soon.