A family of Microsoft word processing software products for creating web, email, and print documents.
If you're trying to use the Split button on the View ribbon, that won't ever work -- that function can only split a single document into two windows that show different parts of one document.
Instead:
- Open documents A and B on one screen.
- With the cursor in document A, hold the Windows key while you press and release the left arrow key. That positions the document in the left half of the screen.
- When you release the Windows key, small versions of the other open documents appear in the right half of the screen. Click document B, which expands to take the right half of the screen.
- Drag document C to the other screen. Repeat the Windows key/left arrow/right arrow process to display documents C and D in the left and right halves of the second screen.