There are different degrees to which you can uninstall Microsoft Windows SharePoint Services. Depending on your needs, you can choose from the following options:
-Remove Windows SharePoint Services from a virtual server and preserve the site content.You can choose to remove Windows SharePoint Services, but keep the site content in the content databases. This allows you to extend the virtual server again later and reconnect to the site content. If you leave the content databases intact, you can reconnect to them, from the same virtual server or from a different virtual server, and continue hosting the site content using the same Uniform Resource Locator (URL). Use this method to temporarily remove and then restore a virtual server, or to change which virtual servers are hosting which content in a server farm setting.
-Remove Windows SharePoint Services from a virtual server and delete the site content.You can choose to remove Windows SharePoint Services and delete the site content in the database. Use this method to remove a virtual server permanently, but continue using Windows SharePoint Services on other virtual servers. For example, use this method if you are finished with a project and no longer need the associated Web sites.
-Uninstall Windows SharePoint Services completely from a server.
You can choose to uninstall Windows SharePoint Services by using the Add/Remove Programs control panel. This method does not delete site content. You can reinstall and reconnect to the site content. Use this method to repair an installation or to remove a Web front-end server from a server farm.
Removing from a Virtual Server by Using HTML AdministrationTo remove Windows SharePoint Services from a virtual server by using HTML Administration, you use the Remove Windows SharePoint Services from Virtual Server page.
Remove from a virtual server
-Click Start, point to All Programs, point to Administrative Tools, and then click SharePoint -Central Administration.
-On the Central Administration page, under Virtual Server Configuration, click Configure virtual server settings.
-On the Virtual Server List page, select the virtual server you want to configure.
-On the Virtual Server Settings page, under Virtual Server Management, click Remove Windows SharePoint Services from Virtual Server.
-On the Remove Windows SharePoint Services from Virtual Server page, select one of the following:
-Remove without deleting content databases
This removes only the Windows SharePoint Services folders from the virtual server — the content database remains intact, so you can reconnect to it later using the same virtual server or a different one.
-Remove and delete content databases
This both removes the Windows SharePoint Services folders from the virtual server and deletes the content database. You will not be able to reconstruct the sites previously stored on that virtual server unless you have a backup.
-Click OK.
Removing from a Virtual Server by Using the Command LineYou can use the unextendvs operation with the Stsadm.exe command line utility to remove Windows SharePoint Services from a virtual server. The unextendvs operation takes the -url parameter and the optional -deletecontent parameter. When you use unextendvs without the -deletecontent parameter, it leaves the content databases in place, so that you can reconnect to the content for a virtual server. When you include the -deletecontent parameter, the content databases are removed and the virtual server is removed from the configuration database.
For example, to remove Windows SharePoint Services from a virtual server, but preserve the content databases, use the unextendvs operation with syntax like the following:
stsadm -o unextendvs -url
http://servernameTo remove Windows SharePoint Services from a virtual server and remove the content databases permanently, use the unextendvs operation with syntax like the following:
stsadm -o unextendvs -url http://servername -deletecontent
Note:-When you use the unextendvs operation with the -deletecontent parameter, you cannot reconnect to the site content later.Uninstalling from the Server ComputerIf you want to remove Windows SharePoint Services from a server computer entirely, you can uninstall by using the Add or Remove Programs control panel. Uninstalling Windows SharePoint Services does not remove any chained products that were installed, such as WMSDE. You must uninstall these programs separately.
Uninstall-On the server computer, click Start, click Control Panel, and then click Add or Remove Programs.
-Select Windows SharePoint Services, and then click Remove.
When you use the Add or Remove Programs control panel to remove Windows SharePoint Services from a server, it calls a command-line operation, stsadm -o uninstall, to perform the task. The uninstall operation does not remove any chained products that were installed. The uninstall operation takes the optional -deletecontent parameter. When uninstall is used without the -deletecontent parameter, it leaves the content and configuration databases in place, so that Windows SharePoint Services can be reinstalled, and you can reconnect to the databases and continue hosting sites. When the -deletecontent parameter is used, the content and configuration databases are removed, and you cannot recover the site content.
Refferance:-
http://technet.microsoft.com/en-us/library/cc288469.aspx