It's also available from the link below:
Panasonic PV/NV-GS300 USB camera driver
OS Supported by this driver: Windows 2000 and Windows XP
File name: NV-GS300USB_Driver.rar
File size: 16523 KB.
Driver Version: 2.02.0000
File date: 06/30/2005
Unrar the file to a temp folder and launch Setup.exe to start the install program.