Try not to open too many programs while working on your computer. The more things that are open, the slower your system will run.

Whenever you are in the market for a newer computer, be aware that cheaper is not always better. Cheaper usually means a slower processor, less memory and not as much hard drive space as a more expensive system. For home use probably ok but for serious use to run a home business not ok.
You will need better and faster equipment for that and you will have to spend a little more for the extra computing power.