You have three options to save a file to Drive from your Windows computer...
Option 1: Drag & Drop
-Go to your drive account in an internet browser like Chrome
-Open a file browsing window on your computer
-Locate the file you wish to save to the drive
-Click on the file once, and while holding down the mouse button, drag the file over to the internet browser screen with your drive account, then release the mouse button.
-A notification should then pop up showing the upload/complete statuses.
Option 2: Upload via Drive online
-Go to your drive account in an internet browser like Chrome
-On the left side of the window, click the red button with an up arrow, next to the "Create"button.
-Select Files or Folder, depending on what you want to upload
-Find the file you want to save to Drive in the file browsing window that pops up
-Click Open
Option 3: Install Google Drive Sync on your computer
Just follow the instructions at the link below. This will create a folder on your computer that syncs with your online Drive account. When you go to save any file, you will browse for the Drive folder on your computer, just like any other folder. Anything you save there should sync with your online account.