product key not valid, new hard drive, win 7 pro oem

I have an HP Pavilion Elite and the hard drive died. I just bought a WD 1T Caviar Black to replace the Seagate drive that was there. The machine had been on Vista. The Vista recovery disks did not work, and would have required 2 years worth of updating even if they had. Since I had intended to move to Win 7 anyway, I bought an OEM Win 7 Pro disk. All has looked fine until I got to the product code. It says the product code is invalid, although it matched what was one the OEM disk case. Regardless, I have carefully checked and re-entered but still get the same result. What do I do next? I saw somewhere about using the Win logo key and "R" to invoke the Run command so I could enter a "slui 4" command to get a phone number to call. However, logo + R only gets me an R entered in the product key field and does not bring up the Run box. Suggestions, anyone?

In the United States the number is: 1-888-725-1047

To get the command to work correctly try clicking on the Start Orb in the lower-left corner (windows logo) and type SLUI 4 in that line command window.