I would like to know if is it possilbe to disable a menuStrip on windows forms? But not whole, I would like to disable only one specific menu.
I know I can disable whole with:

this.menuStrip1.Enabled = false;

Look at this image - I would like to disable menus:
- "Shrani novo datoteko" and
- "Shrani besedilo"

Is this possilbe?

"Shrani novo datoteko" and "Shrani besedilo" are of type ToolStripMenuItem. This type has also an Enabled property. If you want to disable both you perhaps better set the Enabled property to false of the "Shrani" ToolStripMenuItem.