Juniper Allegro CE Owner's Manual page 166

The C_MyDocs and C_Program Files folders were created for you to
use in place of the My Documents and Program Files folders that are in
the RAM file system. The C reminds you that these files are on the
C_Drive, which is a safe area to store data.
RAM File System
The storage ability of RAM may be temporary. If the batteries are
drained or removed, or a Restore System utility is performed on the
Allegro, information stored in RAM can be lost. (The super capacitor
behaves like a backup battery and can maintain the RAM for up to
five minutes while you change the batteries.) From the Desktop,
double-tap on the My Computer icon. The following folders have been
provided:
All of the folders are stored in RAM except for C_Drive and
PC Card.
Page 4-106 Windows CE