Bizarre duplicate/virtual files in Win7

[Friar Broccoli]

I have just noticed some utterly bizarre behavior in Win7 (I just
upgraded from Win98 two weeks ago).

Anyway in two shortcuts to the DOS/commandLine prompt; one as
administrator, the other as an ordinary user, when the ordinary user
saved to C:\ it actually went to

c:\users\MyUserName\appdata\local\virtualstore

unless a file of the same name already existed on C:\ in which case
the write failed.

As an administrator the file actually saves to C:\. If the system
always behaves this way, configuration changes to some programs must
sometimes fail to be written to the system. What a mess.