The official Microsoft public beta links are still not up, due to very heavy traffic (a problem getting the up-to 2.5 million public testers) as a result of interest in the Windows 7 Beta. However, exclusive access to TechNet Plus and MSDN subscribers are still accessible. 

If you cann’t wait until the Windows site up for download, here’re the steps to acquire Windows 7 – official way:

Download: Windows 7 x86 32bit | 64 bit

Steps to acquire Windows 7 Beta license key:

1. Visit TechNet Downloads, sign in at the top right and let the page load
2. Within the same window copy and paste https://www.microsoft.com/betaexperience/scripts/gcs.aspx?Product=tn-win7-32-ww&LCID=1033 into the address bar (yes it's a 32bit key but will work on 64 too, or just simply replace 32 in the link with 64).
3. If you get an server busy error, just press F5 to refresh a few times, until you past through. If you are still having issues try clearing your temp files and deleting all cookies. Note: if you’re being redirected  then you didn’t follow the steps 1 and 2 correctly!
4. If you followed the steps correct you should see your key (depending on your version it could also say Windows 7 Beta 32-bit Product Key  ). Have fun!

Important: Microsoft is also providing a QFE patch for the MP3 corruption issues that have plagued build 7000, this should be online shortly as KB961367. It's extremely important you apply this patch.

Source:→ Neowin