The following was provided by DelKreuz at Optimize files for speed and size :
Granado Espada has a very poor update system. When an update is done, it merges the new ipf files with the old ones, and keeps the old data.
Those old data can be safely removed. Doing so has two advantages :
1 - You earn some disk space.
2 - It can improve your game loading performances.
Here is a small script that will optimize your ipf files, it is very effective for old installations. I had an installation that was made during GE v5.0, and using this script I earned about 1GB, and I saved over 450MB on a fresh install of Granado Esapda Europe!
The file : optimize ge.zip
Everything you need is explained in the readme.txt file, but if you need help feel free to ask by commenting this article!
Note that the process takes quite a bit of time, so you better not launch it if you want to play right away. Windows8 users might have to disable Windows Smartscreen ( Control panel -> action center -> Windows smartscreen)
For those who have problems with reading a readme... This how you should put the files to make it work.
And DO NOT FORGET to use clean-backup.bat to delete the backup files, or you will have doubled the size of your GE instead of reducing it.