Whenever posting questions on these forums, please give us as much information as possible about your computer. Depending on your issue, we might need the operating system, processor speed, amount of RAM installed, brand name of the computer, (if there is one), and any EXACT error messages you are receiving. Which antivirus program are you using and which version? Is it up to date The more information you give us, the better informed our answer will be.

In the meantime, since you're getting the resource message, please follow the instructions in BOTH links below.

How To Shut Down Unnecessary Start Up Programs

How To Clean Unwanted Files From The Hard Drive

Hope this helps and let us know more.