JSI Tip 10573. Some environment variables do not expand in the registry on Windows XP?

When you attempt to expand environment variables in the HKEY_CURRENT_USER\Environment registry key, some variables do not expand.

This behavior will occur if you change environment variables in the Properties dialog of My Computer and you have multiple dependencies, like environment variable EnvC is defined as %EnvB% and environment variable EnvB is defined as %EnvA%, causing EnvC to be dependent on how EnvA is defined.

To work around this issue, only use one level of environment variable dependency.

NOTE: This same issue effects the Longhorn and Vista betas.