Hi,
I'm really not up on the express tools, but I saw that your question has gone unanswerd for a few days, so here goes. If I recall, the tool is accessed as an aspx page through your localhost, so you'll want to make sure you have browser options like allowing script and cookies set accordingly. I don't know if you need to aspnet_regsql.exe and make sure that you have SQL Server Express loaded if it wasn't already. (explore your hard drive and or control panel - add/remove programs to see find these, and search msdn2.microsoft.com to see how and why to use them).
If none of this helps search for info on the tool in MSDN.
Search these forums using appropriate keywords
Then, if you're still stumped, try resubmitting your question. Getting someone to see answer a post is a bit of luck and timing, so if you need to, repost (maybe with different subject line or phrasing), after a few days with no answer.
Good luck. BRN..