the program i mentioned-https://market.android.com/details?id=it.medieval.blueftp&feature=search_result
this will allow you to completely explore your computer (within the allowed folders) and add/delete/modify folder contents from your phone.
(from microsoft support website. not using the bt transfer app)
Receiving a file
To receive a file from another computer, follow these steps:
Click Start, click Run, type %windir%\system32\fsquirt.exe, and then click OK.
In the Bluetooth File Transfer Wizard, click Receive a file, and then click Next.
You receive a "Windows is waiting to receive the file" message.
On the sending computer, click Next to start the transfer.
Note During the transfer, a progress bar appears on the sending computer. When you transfer a file to a Windows XP-based computer, a progress bar also appears in the Bluetooth File Transfer Wizard.
On the Save the received file page, type the name of the file in the File name box, click Browse to select the location where you want to save the file, and then click Next.