Install.txt outdated, contains broken links
On Windows, we prefer you use the more recent stable release, which can always be found at https://tortoisehg.bitbucket.io
That's a broken link.
And at the end:
For source install details, see: https://bitbucket.org/tortoisehg/thg/wiki/developers/Home
That's another broken link.
To upload designs, you'll need to enable LFS and have an admin enable hashed storage. More information