Remove your email from the post if you don't want it to be bombarded with botmail.
Windows Mail and Outlook Express aren't included in Windows 7. To use your email, you'll need to install a new program. You can download Windows Live Mail for free (if it's not already installed on your PC), or you can get a program from another company.
A better option would be to install MS Office and configure Microsoft Office Outlook as your default Mail Client. It's nearly the same as the Outlook Express used to be, just has a lot of more better features and is simple as ever to use.
If you really can't do without the Outlook Express format the nearest available is Microsoft Outlook, usually part of Microsoft Office, which is a bit expensive. There are cheaper bargains to be had for a stand alone versions of Outlook, you need to look for them on Ebay or Amazon, the cheapest probably Outlook 2003. The cheapest I've seen is for Outlook 2000, (£20 at Amazon)but as that was written for older versions of Windows may not run. (Probably would in Compatibility Mode if you have Win 7 Pro)