METHOD 1: Using Keyboard Shortcut
You just need to press "ALT+SPACEBAR" keys together and it'll open the System Menu which shows minimize, maximize, restore, close, size and move options.
Once you get the menu, you can use arrow keys to go to the desired option and press Enter key.
For example, to move the window select "Move" option (or press m key to select the option) and then you can use arrow keys to move the program window to left, right, top or bottom.
Similarly, to resize a large and wide window, select "Size" option (or press s key to select the option) and then use arrow keys to resize it.
METHOD 2: Using Mouse
If you don't want to use keyboard shortcut, you can use your mouse to access system menu. Just right-click on the program button present in Taskbar. Windows 7 users will need to press SHIFT key while right-clicking on the program button otherwise it'll bring jumplist.
Right-clicking on the program button will show the same system menu and then you can click on the desired option but you'll still need to use arrow keys to move or resize the program window.