Error installing latest version of TeX Live on Windows 10
I had the same Problem. It was caused by MinGW, more specific by xz from the MinGW Installation. I just renamed the xz.exe (you could probably also just temporarily remove the mingw path from the path env) so the texlive installer wouldnt use it and i later restored it to the original name.
An indicator could be the detailed output of the installer (install-tl-windows -gui text -v -no-cls). At the beginning the installer is looking for the setup programs. If you see a line like this:
D:trying to set up system xz, arg --version
D:program xz found in the path*
and also have a line like tar: Skipping to next file header (indicates that the tar is corrupt) at your previous error output/log this might will fix your issue. You can verify the usage of the shipped xz by looking at the detailed output again - it should print (after renaming the other(MinGW) xz.exe) something like this:
D:program xz not usable from path
D:(w32) trying to set up xz, default I:/tlpkg/installer/xz/xz.exe, arg --version
D:Using shipped I:/tlpkg/installer/xz/xz.exe for xz (tested).*