Exchange setup error

[Pax]

I'm trying to upgrade an Exchange 5.5 server to 2000. I started the
'setup /forestprep' on the DC, and on the screen where Service Account
name and password is required, mistakingly I type and extra ''
(slash).
Now whenever I retry 'setup /forestprep', I reach the same screen but
the service account is read from somewhere and it will not allow me to
change it.

I searched the registery and the Exchange setup log, but there's
nothing.
Also I used ADSI and followed the insturctions of

http://support.microsoft.com/default.aspx?scid=kb;EN-US;Q283027
http://support.microsoft.com/default.aspx?scid=kb;EN-US;Q273478

but nothing was found.

Does any one have any clue about this, or at least where else Exchange
setup might record setup info?

thanx