On MS Office 2003 or 2007 Service Pack once installed cant be uninstalled unless you remove whole Office product, but in MS Office 2010 you can remove SP1 using control panel.
Many users of MS Office have complaint about many bugs when they installed Service pack 1.Now Microsoft has released the uninstaller to remove the SP1 from your computer easily.
The Microsoft Service Pack Uninstall Tool for Microsoft Office 2010 Client Applications is a command line tool which will assist with uninstalling client patches installed by Office 2010 service packs.
The Office 2010 SP Uninstall Tool is contained in a package called Office2010SPUninstall.exe which is a self-extracting executable file. The tool itself is a single file called OARPMan.exe. There is no installation for the tool. OARPMan.exe, the Microsoft Software License Terms (previously known as End User Licensing Agreement or EULA), and the Readme.txt files will be extracted to the location you specify.
Note that you must use a subfolder such as C:subdir to expand the tool. You cannot expand the tool into the root directory of the hard drive (for example, C:).
Once the tool has been extracted to a folder on the computer, it may be run from a command line. For information on the workflow, refer to the readme.txt file, which should be extracted to the same location as the tool.