Check how many workspaces, charts and studies are you running simultaneously. Some setups, like multiple Volume bars charts (used in Bill Schamp’s workspaces) are known to be very resource-demanding.
Check the CPU load in Windows Task Manager. If it is constantly high, one thing to do is go to Format Study, Properties tab and uncheck the “Update on every Tick checkbox”. Repeat for every study on every chart, save workspaces.
Now the studies will be calculated not on every tick, but on every bar. This will decrease the load on your system.