To save your email folders and address book...
Copy Mail Files to a Backup Folder
To make a backup copy of your Outlook Express e-mail message files:
On the Tools menu, click Options.
On the Maintenance tab, click Store Folder.
Select the folder location, and then press CTRL+C to copy the location.
Click Cancel, and then click Cancel again to close the dialog box.
Click Start, and then click Run.
In the Open box, press CTRL+V, and then click OK.
On the Edit menu, click Select All.
On the Edit menu, click Copy, and then close the window.
Right-click any empty space on your desktop, click New, and then click Folder.
Type mail backup for the folder name, and then press ENTER.
Double-click the Mail Backup folder to open it.
On the Edit menu, click Paste.
Close the Mail Backup window.
Export Your Outlook Express Address Book
On the File menu, click Export, and then click Address Book.
Click Text File (Comma Separated Values), and then click Export.
Locate the Mail Backup folder that you created.
In the File Name box, type address book backup, and then click Save.
Click to select the check boxes for the fields that you want to export, and then click Finish.
Click OK and then click Close.
To Import them use the Import wizard on the File
To save your Email accounts goto Tools menu>Accounts, highlite them one at a time and export them to wherever you want to save them. Then when you have reinstalled OE you can import them all back.
I usually put them all on a USB memory stick and back them up on a regular basis.