1. Open file  "CuteEditor/CuteEditor_Files/include_CuteEditor.asp"

2. Update following in line 941 & 961 (or search for iframe to change width).

3. Look for width:100% and change to  width:500Px

 

(You may use aling=center in above row to look better. To wrap down the tool bar you need to edit this table and toolbar)