Why does Mswin.exe hog my CPU resources?

After a while it just pegs itself in the 90% range even if I close all charts. A pop up reads “Warning! This application is having difficulty keeping up with current real-time data flow. Terminate any nonessential applications or reduce the number of real-time symbols being maintained by this application."

Click on TOOLS | OPTIONS | REAL-TIME | CONFIGURE SERVER | FILE UPDATES

Make sure you do not have any folders selected there.  Also, check your Expert formulae for excessive use of the MetaStock PREV function.

Why should this folder be unchecked?  Because all the securities in that folder are updating real-time, so if you happen to have 50 symbols in that folder, you have 50 securities that update real-time for every single tick of data.  Most computers can only handle a handful of these securities, if even that.