If you'd like to do an advanced search, select Applications - > Google Desktop. The main Google Desktop page should open in your browser. If it doesn't, select Applications - > Google Desktop - > Google Desktop Preferences and when the preference window opens, click the Google Desktop icon in the upper left of your screen.
Select Advanced Search.
On the search page that opens, specify the type of results you're looking for by selecting the appropriate radio button, and either select from the drop-down menu, or type in the requested information.
Type the words you want to search for in the text box labeled 'Has the words', and type any words you want to exclude in the text box labeled 'Doesn't have'.
Click Search Desktop.