I can't activate the windows (Error code: 0xC004F034)

There was an issue with the activation servers which was being investigated.

If you cannot active with the new keys then you will need to phone activate.

If the correct key did not work then you (update)

Windows + R  (keys for run) and type the following command and press enter (for phone activation)

slui.exe 4  

http://answers.microsoft.com/en-us/insider/forum/insider_wintp-insider_install/product-keys-for-windows-10-insider-preview-build/8596c6dc-bdb4-4e33-b6eb-bc02e8f165c1

We are changing the product keys that are used in the Insider Preview, beginning with Build 10158.

If you do a build-to-build upgrade through Windows Update, we were not expecting anyone would need to enter a product key.  But if you are prompted for a product key on Build 10158 or a later build, the new keys are:

For Windows 10 Insider Preview Home Editions: KTNPV-KTRK4-3RRR8-39X6W-W44T3

For Windows 10 Insider Preview Pro Editions: 8N67H-M3CY9-QT7C4-2TR7M-TXYCV

For Windows 10 Insider Preview Enterprise Editions: CKFK9-QNGF2-D34FM-99QX2-8XC4K

ISO files only become available once a build is released to the Slow setting.  So the product key listed on the ISO download page at this time is still for Build 10130.  Once Build 10158 is released to the Slow setting and the new ISO files become available, the product keys listed on the download page will be updated. 

It should also be noted that beginning in Build 10158, clean installs of Windows 10 Insider Preview will prompt you to enter the appropriate product key during setup to activate Windows.