outlook express email files location (in winxp)

Outlook's email files located at:
c:\Documents and Settings\<user name>\Local Settings\Application Data\Identities\{7D43530B-D505-438E-8661-3C8CF2FF2540}\Microsoft\Outlook Express\
files have extention *.dbx

Outlook's Contacts file located at:
c:\Documents and Settings\<user name>\Application Data\Microsoft\Address Book\<user name>.wab
 
Microsoft Outlook default pst location:
c:\Documents and Settings\<user name>\Local Settings\Application Data\Microsoft\Outlook\

more help at http://support.microsoft.com/kb/270670