Your OE emails in XP will be in the following folder by default:
C:\Documents and Settings\[your username]\Local Settings\Application Data\Identities\[long-code]\Microsoft\Outlook Express
If you cannot view it, you'll need to enable 'Show hidden files and folders' in Folder Options (please ask if you need to know how).
Copy the OE folder to a USB flash drive, then from there to a suitable area on your Win7 PC - the C:\ drive is fine.
Open WLM on your Win7 PC & select File > Import > Messages > ....When you're asked to Browse to the suitable OE6 folder, browse to C:\Outlook Express & follow the wizard to completion. G