That link provided by Togo is appalling! (It's Microsoft I'm criticising here, not Togo!!!). It basically says "We don't offer that email client (which works with any email provider's service) any more but, hey, why not switch to our own web-based email system? It's totally different, and therefore not at all what you're looking for, and it's basically the old Hotmail - but we changed the name because Hotmail had such a bad reputation".
If Microsoft actually wanted to offer an equivalent product to Outlook Express (which will still continue working anyway), they should have suggested either their own email client (Windows Live Mail, or similar) or a third-party program, such as Thunderbird. Offering a web-based system as an alternative is ridiculous!
Anyway, to get back to your existing problem, JB, if Outlook Express has simply lost the instruction to display your contacts, this simple fix should work:
http://email.about.com/cs/oetipstricks/qt/et032601.htm
If it doesn't, it means that Outlook Express no longer recognises that a contacts list even exists. However it will still be on your computer but you'll need to import it back into your computer. Here's how:
First, since your contacts list is normally a hidden file, you'll need to ensure that you can see it. To do so, go to Start > Control Panel > Folder Options > View. Ensure that there's a tick next to 'Show hidden files'. Click 'Apply' and 'OK'
Then use the search box to look for *.wab
That should find your contacts list. Note it's location.
Then open Outlook Express. Go to File > Import > Address Book (wab)
Navigate to the location that you noted down and double-click on your contacts list file.