When installing Service Pack 1 (SP1) for Windows 7 or Windows Server 2008 R2 you might get an "Installation was not successful" error message. The most common causes of this problem are:
An inconsistency in the Windows Servicing Store. The Windows Servicing Store is a feature that is required to successfully install the service packs.
A program on your computer, such as an antivirus or antispyware program, is interfering with the installation of the service pack.
To solve this problem, try to install the service pack again after doing each of the following:
The System Update Readiness Tool can help fix problems that might prevent Windows updates and service packs from installing. To download and run the tool, click the link in the table that corresponds to the version of Windows running on your computer.
Click the link in the table that corresponds to the version of Windows running on your computer.
Windows 7 32-bit (x86)
Windows 7 64-bit (x64)
Windows Server 2008 R2 64-bit (x64)
Windows Server 2008 R2 Itanium-based
On the Microsoft Download Center webpage, click Download.
If you see a message indicating that validation is required, click Continue and follow the instructions on your screen. Then, click Download.
Do one of the following:
To install the program immediately, click Open or Run, and then follow the instructions on your screen.
To install the program later, click Save, and then download the installation file to your computer. When you're ready to install the tool, double-click the file.
In the Windows Update Standalone Installer dialog box, click Yes or OK.
In the Installation complete dialog box, click Close.
Try installing the service pack again.
The tool can take several minutes to install. Even if the progress bar appears to stop, don't cancel the installation.
If your computer is having problems finding and installing operating system updates, the Windows Update troubleshooter might be able to fix the problem.
Disabling antivirus or antispyware software might increase your security risk. We recommend that you turn this software back on as soon as possible. If you're connected to the Internet or a network while your antivirus software is disabled, your computer is vulnerable to attacks.
Close all programs, and then restart your computer.
After restarting, turn off all antivirus and antispyware programs that might run during the startup process.
You can usually turn off the program from the notification area, at the far right of the taskbar. To turn off a program from the notification area, right-click the program icon, and then click Close, Disable, Exit, or a similar option. If these options aren't available, you might have to open the program, and then turn it off using options from within the program.
As soon as you close the antivirus or the antispyware program, try to install the service pack again.
After you've installed the service pack, turn on all antivirus and antispyware programs.