add warning about space in filename

README.md

@@ -81,6 +81,10 @@ http://l2ork.music.vt.edu/main/?page_id=56#install-dev
 
 #### Windows 32-bit Using msys2
 Time to build: *roughly 1.5 hours*
+Important note: check the name of your Windows user account. If it has a space
+in it-- like "My Home Computer" or "2nd Laptop", then **stop**. You may not
+use this guide.  (Actually you can probably just install everything in ~/.. in
+that case, but I haven't tested doing it like that. Sorry. Get a better OS...)
 1. Download and install [msys2](https://msys2.github.io/) *(5 minutes)*  
   There are two installers-- one for 32-bit Windows systems (i386) and one for
   64-bit Windows (x_64). Be sure you know which