[dba-Tech] reconnect/logon to network drive

A couple of our XP PCs go for days or weeks between reboots, and 
sometimes they "forget" network drives they connected to at bootup, 
which is a pain eg for backup scripts. Three questions about this:

1. What can we do to prevent these XP boxes dropping network drive 
connections?

2. Google finds lots of vbs scripts for mapping network drives, but not for
--- reconnecting to an already mapped network drive
--- logging onto a mapped network drive that the user hasn't yet logged 
onto manually.
Anybody know where to find them? TIA.

PB