I suggest getting a new USB DAQ system. I've been using FTezDAQ from Futek Instruments. They are fully compatible with VB, Visual Studio and Visual Studio .NET, including examples for Visual C++, Visual C#, and Visual Basic .NET. All of their usb products comes with hardware, software, driver & usb cable. They support Window XP, Vista, Window 7, etc... They support up to 24-bit ADC, 4 Differential / 8 Single-Ended Analog Inputs.
You can find out more on their website at www.futekinst.com. Complete USB DAQ kit start at $69. I've used their products for years. They are very user-friendly. Hope this helps!