In some cases, the computer and HTC Sync Manager may not be able to recognize the phone right away after it is connected. If this happens, try out the tips below which may help solve the problem.
Or, open the Notification panel, tap the Use USB for notification, and then tap File transfers or Transfer files.
Open HTC Sync Manager as an administrator, or make sure you're logged in on your computer as an administrator.
If prompted by User Account Control, then click Yes to apply permission to allow the program to run with full
permission as an administrator.
Check for the latest version and install the update.