download it from here-http://tools.google.com/dlpage/cloudconnect

You can now synchronize your Google Documents with Microsoft Office on your computer with Google Cloud Connect. It is a free plugin that allows you to do that with ease.
It helps you to share as well as backup your documents in a few clicks. After installing this plugin, you can see Google Cloud Connect Toolbar in your MS Office apps. Now, whenever you create a document on MS Office, you can directly upload it to your Google Docs account using the Cloud Connect Toolbar. You will be able to edit and save the changes to the same document later also. It supports all recent versions of MS office (.doc, .docx, .xls, .xlsx etc.).

• After installation, you need to log into your Google account first, by clicking “Login” on the right side of the toolbar. Google may ask you to grant access to the application. Click on Grant Access to continue. 
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• You can obtain the menu by clicking Google Cloud Connect button below the file menu in any MS Office app like MS Word, MS Excel and more.
• The first menu item “Open from Google Docs” lets you choose files to be opened from your Google Doc account.
• You can log out or switch accounts, change Global Document Options and Saving options from the “Google Cloud Connect Settings” option in the menu.

However, it has some limitations too. It can sync the only documents that are supported by MS Office, not the ones that hold the Google Doc format and the ones that are uploaded using Cloud Print. But it can be ignored as the plugin is worth backing up and uploading MS Office documents in no time.