The Google Drive folder that syncs with your online Google Drive account is usually inside your user profile folder at C:\Users\{your user name}. Right click it and choose "Include in Library" and add it to some library so it is indexed. Or instead of adding it to a Library, open Control Panel -> Indexing Options. Add this folder to the indexed locations using the Modify button.
See this search box usage guide to understand how the search works and how to include additional folders:
viewtopic.php?f=4&t=1588