RIGHT click on a blank area of the desktop, choose "Properties", then click on the "Screen Saver" tab. Once there, UNCHECK the box that says: "Upon resume, password protect". Now, click the "Power" button, then the "Advanced" tab. When that opens, UNCHECK the box that says: "Always prompt for a password when computer resumes from standby". Now click on the "Power Schemes" tab and adjust the various power items to your personal preference.. It sounds like it's going into Standby too quickly and you may want to adjust the "System Standby" item to something better for you.. Personally, I'm not a fan of Standby and change that listing to "Never" but that's your personal choice. Once you're got your preferences set, click on "Apply", then OK.
Hope this helps.
We have an old Dell laptop. Our uncle gave it to us along with the manager's user name and password. It has Windows XP Professional OS. It had been unused until we hooked it up just to use a Magic Jack. After several minutes being dormant a box comes up that says "Computer locked. This computer is in use and has been locked. Only manager or administrator can unlock this computer. Press ctl+ alt + del to unlock". Once I do that I get the box that allows me to enter the mgr's. user name and PW. Once the laptop goes into an automatic lock down mode the magic jack won't work. I've increased the power and hard drive shutdown time to never. I'm sure there's a simple fix to eliminate the lock down feature but I'm clueless and would appreciate the help.