What Software Can I Uninstall From My Laptop to Free Space ?

Keep the Visual C++ Runtimes. You may run into other programs that may use them. Remove the ACER software as suggested earlier. These programs though, do not consume much space on the computer to make a noticeable difference.

From within windows you can run "Disk Cleanup" to clear out items such as:

Temporary Internet Files, Windows Update Cleanup Files, etc...You may regain some of your space in this manner.

If you have files stored within the Documents, Pictures, or Downloads sections, you may see if you can perform a backup to hard drive/flash drive/DVD if possible and remove them off the computer to free up space until you can update. Then you can copy them back onto the computer.