"Your current security settings prohibit running activex controls on this page. As a result the page may not display correctly" in outlook 2000.

Outlook 2000 takes its security settings from the restricted sites area of Internet Explorer and yet changing the value for enabling Active X in the Internet options control panel does not stop the "Your current security settings prohibit running activex controls on this page. As a result the page may not display correctly" error message from appearing.

Instead open Outlook, click on Tools and then options. Select the security tab and then in the security zones area you will notice that Outlook uses the restricted zones area. Click on the zone settings button, say OK to the warning message that pops up and then click on the  Custom level button. Change [Run Active X controls and plugins] to enable. Note that this does reduce the security of your computer so if this is acceptable to you then click OK.

You will now be able to create a new email without the error message appearing. 

It is quite likely that any signature you have created shall have an x rather than a picture you have inserted.

Try copying the signature from someone else in the same firm and paste using edit rather than advanced edit in Outlook. Alternatively create the signature in Word and then paste using edit rather than advanced edit.