I searched in google for this but i don't know if its right?

When i run my unattended windows 7 version i stil get the question to enter the product key.

In google i've read that it is possible to do it with the next text.

<ProductKey>
  <WillShowUI>OnError</WillShowUI> 
  <Key>xxxxx-xxxxx-xxxxx-xxxxx-xxxxx</Key> 
  </ProductKey>

Can somebody tell me if this works or stands the X for a number so nobody can see it?

I want to skip this part in the setup.

Windows 7 is a little different than Vista, and what you're doing won't work. Instead, use this if the key is retail or OEM:

<settings pass="windowsPE">
  <component name="Microsoft-Windows-Setup" processorArchitecture="amd64" publicKeyToken="31bf3856ad364e35" language="neutral" versionScope="nonSxS" xmlns:wcm="http://schemas.microsoft.com/WMIConfig/2002/State">
  ...
	<UserData>
	  <AcceptEula>true</AcceptEula>
	  <ProductKey>
		<Key>XXXXX-XXXXX-XXXXX-XXXXX-XXXXX</Key>
	  </ProductKey>
	</UserData>
  </component>
...
</settings>

If the key is a MAK key, you need to have it in 2 places (sort of):

<settings pass="windowsPE">
  <component name="Microsoft-Windows-Setup" processorArchitecture="amd64" publicKeyToken="31bf3856ad364e35" language="neutral" versionScope="nonSxS" xmlns:wcm="http://schemas.microsoft.com/WMIConfig/2002/State">
  ...
	<UserData>
	  <AcceptEula>true</AcceptEula>
	  <ProductKey>
		<Key></Key>
	  </ProductKey>
	</UserData>
  </component>
...
</settings>
...
...
...
<settings pass="specialize">
...
  <component name="Microsoft-Windows-Shell-Setup" processorArchitecture="amd64" publicKeyToken="31bf3856ad364e35" language="neutral" versionScope="nonSxS" xmlns:wcm="http://schemas.microsoft.com/WMIConfig/2002/State">
	<ComputerName></ComputerName>
	<ProductKey>XXXXX-XXXXX-XXXXX-XXXXX-XXXXX</ProductKey>
	<RegisteredOrganization>Organization</RegisteredOrganization>
	<RegisteredOwner>User</RegisteredOwner>
	<DoNotCleanTaskBar>true</DoNotCleanTaskBar>
	<TimeZone>Eastern Standard Time</TimeZone>
  </component>
...
</settings>

Windows 7 is a little different than Vista, and what you're doing won't work. Instead, use this if the key is retail or OEM:

<settings pass="windowsPE">
  <component name="Microsoft-Windows-Setup" processorArchitecture="amd64" publicKeyToken="31bf3856ad364e35" language="neutral" versionScope="nonSxS" xmlns:wcm="http://schemas.microsoft.com/WMIConfig/2002/State">
  ...
	<UserData>
	  <AcceptEula>true</AcceptEula>
	  <ProductKey>
		<Key>XXXXX-XXXXX-XXXXX-XXXXX-XXXXX</Key>
	  </ProductKey>
	</UserData>
  </component>
...
</settings>

If the key is a MAK key, you need to have it in 2 places (sort of):

<settings pass="windowsPE">
  <component name="Microsoft-Windows-Setup" processorArchitecture="amd64" publicKeyToken="31bf3856ad364e35" language="neutral" versionScope="nonSxS" xmlns:wcm="http://schemas.microsoft.com/WMIConfig/2002/State">
  ...
	<UserData>
	  <AcceptEula>true</AcceptEula>
	  <ProductKey>
		<Key></Key>
	  </ProductKey>
	</UserData>
  </component>
...
</settings>
...
...
...
<settings pass="specialize">
...
  <component name="Microsoft-Windows-Shell-Setup" processorArchitecture="amd64" publicKeyToken="31bf3856ad364e35" language="neutral" versionScope="nonSxS" xmlns:wcm="http://schemas.microsoft.com/WMIConfig/2002/State">
	<ComputerName></ComputerName>
	<ProductKey>XXXXX-XXXXX-XXXXX-XXXXX-XXXXX</ProductKey>
	<RegisteredOrganization>Organization</RegisteredOrganization>
	<RegisteredOwner>User</RegisteredOwner>
	<DoNotCleanTaskBar>true</DoNotCleanTaskBar>
	<TimeZone>Eastern Standard Time</TimeZone>
  </component>
...
</settings>

Is it possible if i put the key part at the wrong place that my autounattended dos'nt work anymore?

I tryed to do your first option in my w7 rtm version but then the script dos nothing also the second option did'nt work.

If i let the part of the product key out if the script then the script works fine.

What could be the problem?

If you add the product key section incorrectly, or in the wrong location, then yes your unattend will fail.

if you are using KMS MS provides temp keys that are used for the intial install and then can be replaced later on either manually or hte machine just registers with your KMS server.

Here are the Windows 7 KMS Client Setup Keys:

Windows 7 Professional - FJ82H-XT6CR-J8D7P-XQJJ2-GPDD4

Windows 7 Professional N - MRPKT-YTG23-K7D7T-X2JMM-QY7MG

Windows 7 Enterprise - 33PXH-7Y6KF-2VJC9-XBBR8-HVTHH

Windows 7 Enterprise N - YDRBP-3D83W-TY26F-D46B2-XCKRJ

Windows 7 Enterprise E - C29WB-22CC8-VJ326-GHFJW-H9DH4

Windows Server 2008 R2 HPC Edition - FKJQ8-TMCVP-FRMR7-4WR42-3JCD7

Windows Server 2008 R2 Datacenter - 74YFP-3QFB3-KQT8W-PMXWJ-7M648

Windows Server 2008 R2 Enterprise - 489J6-VHDMP-X63PK-3K798-CPX3Y

Windows Server 2008 R2 for Itanium-Based Systems - GT63C-RJFQ3-4GMB6-BRFB9-CB83V

Windows Server 2008 R2 Standard - YC6KT-GKW9T-YTKYR-T4X34-R7VHC

Windows Web Server 2008 R2 - 6TPJF-RBVHG-WBW2R-86QPH-6RTM4