Windows Cannot Find the Target

Hi Experts,
Here is my Laptop configuration:
Sony Vaio VGN-FW378J
The Bluetooth installed is: WIDCOMM Bluetooth Software 6.2.0.5800
Windows Vista Home Premium
When I start my laptop, I have seen the following 2 error messages regularly.

btsendto_explorer.exe
Windows cannot find the target
OK

BTTray
ERROR: Unable to start the Bluetooth stack service
OK
Then I searched in goggle, and I think may be the problem in Bluetooth.
Also,I installed the software again but same result. Need some details.
Thanks.
