When you are installing Windows 7 or Windows Server 2008 R2 SP1, the system is required to reboot. During the rebooting and applyting the updates (Applying update operation xxxxxx of xxxxxx), you may encounter the 0xC000009A error and hang. So you can not log into the WIndows any more.
A typical error is like below:
Error C000009A applying update operation 115991 of 316581 (Registry...)
The error 0xC000009A is STATUS_INSUFFICIENT_RESOURCES. The error may be due to too many language pack being installed on the system.
Following the below steps to remove language pack before installing SP1:
1. Click Start and openControl Panel.
2. Open "Region and Language"
3. Selec "Keyboards and Languages" tab.
4. Click "Install/Uninstall Languages"
5. Uninstall display languages except English.
Then you should be able to install SP1. After SP1 is installed successfully, you can re-apply the language pack.
To recover the no-boot situation, you need to do system restore or revert to Windows 7 RTM:
1. Apply System Restore from the Windows Recovery Environment (WinRE)
At boot-up, Hit F8 --> Repair --> System Recovery Options Window --> System Restore
2. If the system restore failed, you can use the following command to revert to Windows 7 RTM running state:
In the WinRE, run the command prompt and run the following command:
DISM /image:C: /cleanup-image /revertpendingactions
05/26 Edit: A hotfix was released to fix this error, please install it. http://support.microsoft.com/kb/2534366