I'm sorry but, the uninstaller at that stage is not doing anything out of the ordinary, other than copying files. The only possible issues I can think of are:
- You are too low of hard drive space on the Windows temporary folder. Even if you chose to install GSX on a different drive, the installer will always first uncompress all its files in the Windows temporary folder, then will copy them to their final destination. This is standard with every installer out there so, if you are low on space on the disk that holds the Windows temporary folder, you are going to have issues with many other installers too. Depending, of course, how many files they need to uncompress.
OR
- You still have some kind of antivirus or similar security product interfering with it. Many users think they have turned off every antivirus, just because they have turned off Windows defender, but they might still have other similar products doing the same thing, which would require being disabled.