How much does it cost to upgrade Windows 7 to SP1?

Question

Windows

Good afternoon everyone, I had such a question. Recently, some programs have stopped running, after reading on the Internet, I found out that most programs are already working under the new Windows 7 Sp1 update. Such a question, the update asks for 8 GB to install this update when I have only 9 GB free ( the volume itself is small only 30 GB), so I ask if this update will also weigh after installation and do I need to add memory to this volume or is it only at the time of installation?
PS The update installation file itself weighs 945 MB