http://support.microsoft.com/kb/947296
"The Support_388945a0 account enables Help and Support Service
interoperability with signed scripts. This account is primarily used
to control access to signed scripts that are accessible from within
Help and Support Services. Administrators can use this account to
delegate the ability for an ordinary user, who does not have administrative
access over a computer, to run signed scripts from links embedded within
Help and Support Services."
http://support.microsoft.com/kb/300692/EN-US
"The Novice computer has a built-in local user account called HelpAssistant.
This account is disabled by default and has a randomly generated strong password.
The account has limited privileges and is used by the Expert to logon to
the Novice computer during the Remote Assistance session."
"The Novice Invites the Expert to Connect to Their Computer
When the Novice's computer creates the invitation file,
the following actions occur:
* The HelpAssistant account is enabled."
"When the Ticket Expires
Remote Assistance disables the HelpAssistant account and removes the Allow
logon through Terminal Services right in one hour. Remote Assistance also
turns off any port mapping on UPnP-compliant NAT devices."
HelpAssistant is also named along with "mebroot" malware. Which is
another angle to consider, if it won't behave itself.
http://forums.pcworld.com/index.php?/topic/64582-helpassistant-folder-keeps-appearing/
Paul