A look at the 'Start' of Windows XP something seems to be missing. One has never thought of it for some time not until one wants to run commands, commands like gpedit.msc, regedit, etc.
Having seen somebody run dxdiag to check the size of RAM installed in a system, clicking on Start only to be presented without RUN to type it in, makes it a must to fix when necessarily possible.
Now, the missing Run command has prompted one to look for ways of finding solution to it. It could have be likely caused by clicking 'Clear' check box of Display Run at the Taskbar or the system is encountering malicious software attacks like Tazebama, etc. However, it is certain finding solution is what mattered most at this point in time.
If the above indications are among what occurred to your Windows XP operating system there is quick step-by-step solution to have it back where it belong and working as it supposed to efficiently.
Image of Start menu with missing Run Command
(a) Clearing check box of Display Run is the cause.
Step 1: Click 'Start' and move to 'Settings'
Image of Taskbar and Start Menu.
Step 2: Click 'Taskbar' and 'Start Menu'
Step 3: Click on the 'Advanced' tab and select 'Display Run'. And click 'OK' to make changes.
If that didn't solve the problem it is probably going to be malicious software attack.
(b) Malicious software is the cause
Step 1: To find solution to that visit this LINK.