In order to proceed with entering of the Text/HTML module, when logged in as an administrator, you have to follow this procedure:
Add New Module and select the Text/HTML module. The following dialog box will be displayed:

In order to enter the text click Edit Text. Select Basic Editor Text Box located above the window and select Text located below the window. Type or paste in the text..
In the Search Summary field (optional), enter a summary to help the Search module
To have a preview of the text Click Preview.

Click Update to save the modifications.