Windows Mobile device stopped syncing - not detected through usb either by Vista or by Windows XP

My Windows Mobile device (HTC TYTN II) stopped syncing - it is not seen via USB by any computer, running either Vista or Windows XP. (Before that, it was syncing with 2 computers for about 4 months). When I tried Bluetooth, device is seen but all attempts to establish connection are futile: the response I have is "Service is not found".

I have tried all recipes apart from a hard reset (soft resets, rebooting any computer, uninstalling and reinstalling WMDC on Vista or ActiveSync on XP, changing options on USBtoPC on my device, etc. Clearly, the problem is with my device as no computer sees it. It looks that hard reset is the only remaining option (as I don't know what to change in Registry file - I can edit it). However, if it will not start syncing after that, I won't be able to reinstall some programs for which I have only .exe files (not .cab).

Anybody can help? Short of solving the main problem, can anybody suggest how can I back up my personal data (e.g., contacts, diary, etc) to a storage card?

Thanks in advance,
 Demure