Sure, go to the command prompt and set the directory to whatever directory
the makecert.exe excecutable is in. The type "makecert.exe" with the
appropriate switches. make sure that you leave a space after each switch like
"-ss loser" and type the resulting cert file at the end with a space between
it and the value of the last switch. If you want the cert to be installed
automatically to the "current user" / "other people" tree, omit the "-sr"
switch. Since you want to use it to encrypt messages I recommend installing
it to the LocalMachine root. S to do that, enter in the makecert.exe with "ss
root" and "-sr LocalMachine" when the cert is finished, close the command
window, double click on the cert file and press the install certificate
button. it should install it to the LocalMachine/Root catagory, if not,
manually select which store to use and put it in the LocalMachine/ "Root
trusted certificates" catagory. There you go! That should do it.

-Kristen