Prolific USB to Serial Adapter not installing

We had a customer who was having problems installing the prolific USb to Serial adapter. For some reason the install couldnt find the drivers. The following instrucitons helped resolve his problem.

1. Open the Device Manager
2. Right Click on USB-Serial controller D
3. Select Update Driver
4. If asked, don't have the hardware wizard search the internet for the driver. And click Next
5. Select Install from a list or specific location. And click Next
6. Select Don't search. I will choose the driver to install. And click Next
7. This next screen isn't always the same. If you see a Have Disk button then click on it. If you see a list of device types only, then double click on the option to Show All Devices, and then click on the have disk button.
8. Navigate to the \Windows\system32\ folder or the \Windows\system32\Drivers\ folder Or to the folder where you download the attached file. It should identify a file called ser2pl.inf.
9. Select that file and click on the Okay button
10. Follow through with the rest of the wizard, having it use the driver you selected.

From here the driver should be installed correctly. The link for the driver files is http://sewelldirect.com/Drivers/SW-1301-XP2K-FILES.zip