How to make finicky 32-bit applications install and run in 64-bit Windows

Certain older 32-bit applications (notably Adobe Creative Suite CS2 apps, but there are probably others) object to being installed in “C:\Program Files (x86)\”, which is where 64-bit Windows wants to put legacy 32-bit apps. The solution is easy but non-obvious, as is true so much of the time. When these programs install and ask for [...]