If you have multiple DBX files, place them in the same folder first and make one more backup before you begin. Don't rename the Inbox.dbx, Sent Items.dbx, Drafts.dbx or any custom folder file, because those names will help you correlate the old Outlook Express folder layout later.
The manual route is not very comfortable here. This method usually requires an old Outlook Express setup and on a new Windows system, the folder order can become messy.
For users who want to bring old Outlook Express folders into Outlook without breaking the mailbox arrangement, GainTools DBX to PST Converter Software gives a safer conversion path. It lets you pick the required DBX file, preview messages, choose the saving location and create PST output that can be opened in Outlook.
Before moving all DBX folders, run the free demo first. Convert 10 emails from each DBX folder and check the folder names, dates and attachments in Outlook.