[Please Help!] MHS Error when Opening Process

Hello everyone!
Here is an image of the error I get whilst trrying to Attach/open Engine.exe with MHS (to edit its memory).



Here is what I've done (prior to the error):

1. Opened C.A.
2. Logged in and stayed in lobby.
3. Alt + Tab'd out, then I right-clicked on the MHS and clicked 'Run As Admin'
4. Clicked File -> open process -> Engine.exe

I get the error at step 4.

Here is some needed info:

• I'm operating on Windows Vista Home Premium.
• I UNINSTALLED Service pack 1 (thought that may have been the issue
• I have the LATEST version of MHS, as well as the latest version of C.A.
• I DON'T have a pesky firewall blocking the actions

Any suggestions/help is greatly appreciated!

Thank you in advance!