In some situation after uninstalling the products also the services created by the product will be still in the windows services list.
So it is good to delete those services after cleaning the machine.
To do so the following are the steps.

Method 1 :

Start -> Run -> type Cmd -> Hit Enter
in command prompt
Type sc delete <servicename>
ex :
sc delete IBMWebsphere

Then don'r forget to reboot the system.
Note : To create a new service
sc create <service name>

Method 2 :(Registry clean)
If you prefer to work in the registry rather than through the command prompt to delete services;

    * Click Start | Run and type regedit in the Open: line. Click OK.
    * Navigate to HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services
    * Scroll down the left pane, locate the service name, right click it and select Delete.
    * Reboot the system