If you played the beta I found this very helpful as it fixed mine completely,

"I was getting the OS below system requirements and I did the following to fix it.
1) Ensured I have all the lastest OS updates for Windows using Windows Update.
2) Show Hidden System Files and go to the ProgramData (NOT ProgramFiles) directory and find battle.net then go to agent and make sure it is not running in compatability mode (this was a previous fix during the beta)
3) Make sure the old D3 Beta files are deleted, this includes the D3 Beta dir
4) The Windows Secondary Logon Service MUST be turned on either auto or manual
5) Run the D3 Installer as Admin

Tada it works, this also resolves the installer stuck at 0% error."

All credit goes to FENRIS!