DrRacket 6.10.1 (64 bit) hangs during opening of rkt files on Windows 10 (with Fall Creators Update installed)

I'm trying to follow along the HtDP class on EdX on a laptop running the latest Windows 10.
https://www.edx.org/course/how-code-simple-data-ubcx-htc1x

I noticed a few issues:

1. It takes a long time to run the installer. Clicking on the Show details button, I can see that it's spending a lot of time writing out HTML files one by one. It feels like it takes more than 3 mins to complete the installation.

2. Execution feels quite sluggish on this fairly fast laptop (this year's Intel Core i5, 8GB of RAM, SSD).

3. When I download the rkt course material supplied and open them in DrRacket (either by double-clicking, or File -> Open), the IDE hangs. Windows shows an "Application not responding" message in the title bar.

4. I tried downloading the same file on my Mac, and it worked fine (also 6.10.1). In addition, I get the laser beams when I hover on the definition area on the Mac, but that doesn't work on Windows.

Reproduce the reported behavior on Windows 10 with Fall Creators Update using DrRacket 6.10.1 and the supplied .rkt course files. Check the installer delay, IDE sluggishness, file-opening hang, and missing definition-area laser beams; done requires determining which symptoms remain and confirming that opening the files completes normally.