Sounds like AutoCAD cannot find the necessary files to use dialogue boxes. You might try using a clean AutoCAD profile.
Go to Options-->Profiles tab and click Add To List on the right. Give a new name and close the dialogue box. Now double click on the new name or select it and click Set Current on the right to activate it. Now click on Reset and confirm you want to reset the profile. Close the Options, close AutoCAD and restart.
Check if the commands now work. If they do, compare the Support File Search Path on the Files tab for both the old and the new profile. If there are any missing add them to the old profile as well, make it current and restart AutoCAD again.
If above doesn't work; I'd noticed you did mention it is your work computer. Are you working only on one and the same PC or do you switch between PC's? Or did you recently got a new PC?
If you did switch or get a new one and you are logging in with a domain username, it could be that AutoCAD is referencing files that are not yet available in your Windows user profile on that specific PC. You probably did get an error message at startup with something like 'missing base.dcl'
Only solution is AutoCAD to force to copy those files again and that can be done with Start --> All Programs --> Autodesk -->AutoCAD 2XXX --> Reset Settings To Default.
If you have no customization at all, you can safely use this to reset AutoCAD without any problems. But if you did make any customization incl. changes to your workspace and/or CUI, depending on your setup and where those files are located, you will lose all your changes unless you make a backup of these. So make sure to check and double check. Use at your own risk!
