I recently bought Garmin Nuvi 2455LT. When I try to connect to the PC, some MTE player starts (on Windows XP SP3 Pro) and device is not recognized on PC (don't appear in My computer), MapSource software can't find it as device.

When I connect the Nuvi 2455LT on PC's with Windows XP SP3 Home Edition and Windows 7 SP1 Home Premium, computers recognize the device as Nuvi 2455 under 'My Computer" but Nuvi device didn't get the letter as other devices in the computer "C, D, E... etc". MapSource can't find the connected device and I can't upload maps into the 2455LT or into memory card that is inserted in the device (in the computer appear without letter)

need some help

Thank you