I tend to keep a lot of Excel spreadsheets open at one time (probably 20-30). I have 3 monitors so i need a few instances of Excel running to show different spreadsheets on different monitors. I noticed that, over time, some of larger spreadsheets tend to slow down when scrolling or entering data. Usually a reboot helps but it got me thinking. I tend to have about 3-4 instances of Excel open with around 6 or 7 spreadsheets in each one because i thought that was a better use of resources. Am i right? Will things run better if i open each spreadsheet in it's own instance of Excel?