I’ve been having the issue too. Been digging in for the last couple of hours (google fu was up to speed today).
Anyway here is what I found.
Windows 7 Pro computer / 12 GB Ram, ATI 4gb video card: No issues on this.
Windows 10 Pro computer / 16GB Ram, NVidea 4 gb video card: Lagged to death. NO error logs to post.
What I found is that by uninstalling my Razor software on the Windows 10 computer, the issue has so far cleared up. I can now finish installing the software. That lag was just eatting up my processing power, it wouldn’t download or install very fast.
Source link that helped me track this down:
https://reshade.me/forum/troubleshooting/1280-solved-need-help-guild-wars-2-launcher-crashes-on-launch?start=6