For a successful installation of the Service Pack (SP1) on Windows 7, possibly, you need to have some prerequisites such as System Update Readiness Tool, enough disk space, disabling antivirus program, etc.
If you got an “Installation was not successful” error message when installing a service pack on Windows 7 and/ or Windows Server 2008 R2, the following troubleshooting guides published by Microsoft may help you.
- Troubleshooting guide for Windows 7/Windows Server 2008 service pack (SP1) installation problem.
- Guide for solving service pack installation issues connected with security programs like Microsoft Security Essentials or Microsoft Forefront Client Security.
- An approach for freeing disk space for successful service pack installation.
The above guides certainly helpful if you have any plans to install the upcoming service pack or Windows update for Windows 7 or Windows Server 2008.