Why Does The Computer Do These Things?

Well, first off... You only use the CTRL-ALT-DELETE method if the program isn't responding in the first place, if you do it just to get out of the program quicker, it could cause problems. Also, with the webpages, do you mean that when you close the webpage then open the browser again the same webpage is there? That happens because of the internet browsers settings, you can change them under your browsers internet settings and/or control center. It's hard to pin point the problem with little detail, what kind of computer? What kind of browser? What operating system? When you close a program with ctrl alt delete I think the program will think it had a error since you did a force quit hence why it will give you that error message. Good luck.