[plt-scheme] bugs in installing Typed Scheme with DrScheme v372 already installed on Windows XP Pro

I would like to preserve my current installation of DrScheme, v372, English, and install v4.0 into a different directory in order to use Typed Scheme.

Currently, I have v372 installed on Windows XP Professional Service Pack 2 (at work) at C:\bin\plt\.  I would rather not delete this installation, and just install DrScheme v4.0 into a different directory.

However, when I tried installing v4.0 into C:\bin\plt-4.0\, I could not find Typed Scheme as a language level in the "Choose Language" dialog found in the "Language" menu of DrScheme.  Trying to install it with the following command (from "Typed Scheme" at http://www.ccs.neu.edu/home/samth/typed-scheme/) at the DrScheme command prompt only resulted in DrScheme complaining of trying to overwrite the existing Typed Scheme installation:

 > (require (planet "typed-scheme.ss" ("plt" "typed-scheme.plt" 3)))

After uninstalling DrScheme 4.0 and reinstalling it, trying to run the following alternative command from the Typed Scheme manual (http://www.ccs.neu.edu/home/samth/typed-scheme/manual/)

 > (require (planet "typed-scheme.ss" ("plt" "typed-scheme.plt" 2)))

caused DrScheme to complain of being unable to find the package at PLaneT.

What should I do to use Typed Scheme in DrScheme 4.0 with v372 already installed (without uninstalling v372)?

Benjamin L. Russell