Default Mail client not properly installed

[jillh1027]

How do i install default mail client?

 

[Onus]

I'm going to assume you're asking about a Windows 7 system, which does not come with an email program.
Get a free one like Thunderbird. Even Windows Live Mail will work, if you don't mind every email you send or receive being out in "the cloud" (i.e. regardless of privacy policies in place today, eventually your data will be made available to be sifted by anyone and everyone for advertising and other purposes).
If your problem is something different, you'll need to elaborate.