So I got some Block Erupter USB sticks for free from a friend.  (They work, he's just going overseas and only had a few to play around with). 

I have an older Windows PC (has Windows 7 on it).  I was following some directions to get it set up to mine (I realize that i'm barely going to mine anything, I only have 4 of the block erupters but I didn't pay anything for them so anything I can get is a great ROI.)

I went through and went to install the drivers here: http://www.silabs.com/products/mcu/Pages/USBtoUARTBridgeVCPDrivers.aspx

But when I download and click the .exe file, I get an error that says: "The device driver installation wizard was unable to find any drivers designed for your machine. Check with the vendor or your site administrator to ensure you have the correct program."

Any advice on what I can do?

Thanks!