When you try to use the runas command at a command prompt in Windows Vista to run Windows Internet Explorer 7, you find that Internet Explorer 7 does not start. When this occurs, you are trying to use the runas command to run Internet Explorer 7 in an account that differs from the one that you used when you logged on to Windows Vista.
This issue occurs because Internet Explorer 7 does not support the runas command in Windows Vista.
To work around this issue, switch to the different user account in Windows Vista, and then start Internet Explorer 7 directly.
To switch user accounts in Windows Vista, click Start, click the arrow next to the Lock button, and then click Switch Users.