Use Regedit.exe and search for NoBrowserOptions and remove it.
It is most likely to be here (but not necessarily)
If you are unfamiliar with Regedit, then ensure you know how to
restore your Registry in case of error and it is a good to export any
key before deleting.
Check the startup (Start-Run-MSCONFIG-Startup tab) for any unknown
items if it is reset on reboot.
You might try this snippet from Mike Burgess first if you use SpyBot:
'Did you by chance run SpyBot's Immunize feature?
If so, you can unlock by unchecking the option to "Protect IE Control
Alan Edwards, MS MVP W95/98 Systems
In microsoft.public.windows.inetexplorer.ie6.browser, "rp"
>From within IE6 (sp1), when I click on "Tools, Internet options" I get
>this error box instead of the menu:
>"This option has been cancelled due to restrictions in effect on this
>computer. Please contact your system administrator"
>I can, however access this menu from the Control Panel, and it has
>always worked in the past inside IE, can't think of anything I changed
>Using W2k, SP3