To perform continuous updated GMM estimation, click on the Estimation drop down menu (just below the program logo) and select the Unrestricted entry. What you should see is the following
The only difference between this window and the unrestricted GMM is that the 1step W field is grayed out; this fied is not enabled any more, since it is not required for the estimation. Note also that the edit box next to the field is also disabled, meaning that you are not able to enter any information in it.
For the remaining fields, you can visit the unrestricted GMM help file to check their definitions.