GNSDK_DSP.DLL Fix
I found the solution to this error. Go to: http://www.2shared.com/file/VPN00U2S/gnsdk_dsp.htm and download gnsdk_dsp.dll, once you've downloaded it you will have to move it into the iTunes file. For those who don't know how to get there, open up "My Computer" - choose your Hard Drive "C:" - "Program Files (x86)" - "iTunes" and drag and drop the downloaded file right into it. That's it! Start iTunes and it will work. This worked great for me, and the download is 100% virus free.
Windows 7, iTunes 10.5 update gnsdk_dsp.dll er