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Disable File Download in Internet Explorer
http://www.winguides.com/registry/display.php/901/
You may also be interested in some of the other hack on this site.
Content Advisor Restrictions (All Windows)
http://www.winguides.com/registry/display.php/1098/
Force Users to Logon to Windows (Windows 95/98/Me) Popular
http://www.winguides.com/registry/display.php/629/
Internet Explorer Restrictions (All Windows) Popular
These settings and restrictions allow you to selectively control a range of
features available in Microsoft Internet Explorer 5 and 6.
AlwaysPromptWhenDownload - Always prompt user when downloading files.
NoBrowserBars - Disable changes to browsers bars.
NoBrowserClose - Disable the option of closing Internet Explorer.
NoBrowserContextMenu - Disable right-click context menu.
NoBrowserOptions - Disable the Tools > Internet Options menu.
NoBrowserSaveAs - Disable the ability to Save As.
NoFavorites - Disable the Favorites.
NoFileNew - Disable the File > New command.
NoFileOpen - Disable the File > Open command.
NoFindFiles - Disable the Find Files command.
NoNavButtons - Disables the Forward and Back navigation buttons
NoOpeninNewWnd - Disable Open in New Window option.
NoPrinting - Remove Print and Print Preview from the File menu.
NoSelectDownloadDir - Disable the option of selecting a download directory.
NoTheaterMode - Disable the Full Screen view option.
NoViewSource - Disable the ability to view the page source HTML.
RestGoMenu - Remove Mail and News menu item.
http://www.winguides.com/registry/display.php/442/
Internet Explorer Control Panel Restrictions (Part 1) (All Windows) Popular
These tweaks allows you to control access to the Internet Explorer setup and
control panel functions (found under Tools -> Internet Options).
Advanced - Prevent changes to advanced settings
Autoconfig - Prevent changes to Automatic Configuration
Cache - Prevent changes to temporary file settings
CalendarContact - Prevent changes to calender and contacts
Certificates - Prevent changes to security certificates
Check_If_Default - Prevent changes to default browser check
Colors - Prevent Color changes
Connection Settings - Prevent changes to connection settings
Connection Wizard - Disable the Connection Wizard
Fonts - Disable font changes
History - Disable changes to History settings
HomePage - Disable changes to Home Page settings
Languages - Disable Language changes
Links - Disable Links changes
Messaging - Disable Messaging changes
Profiles - Disable changes to Profiles
Proxy - Disable changes to Proxy settings
Ratings - Disable Ratings changes
Wallet - Disable changes to Wallet settings
http://www.winguides.com/registry/display.php/537/
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Internet Explorer Control Panel Restrictions (Part 2) (All Windows) Popular
The features available within the Internet Explorer control panel (Tools ->
Internet Options) can be individually managed and disabled using this tweak.
Accessibility - disables all options under Accessibility
GeneralTab - removes General tab
SecurityTab - removes Security tab
ContentTab - removes Content tab
ConnectionsTab - removes Connections tab
ProgramsTab - removes Programs tab
PrivacyTab - removes Privacy tab
AdvancedTab - removes Advanced tab
CertifPers - prevents changing Personal Certificate options
CertifSite - prevents changing Site Certificate options
CertifPub - prevents changing Publisher Certificate options
SecChangeSettings - prevents changing Security Levels for the Internet Zone
SecAddSites - prevents adding Sites to any zone
Privacy Settings - prevents changs to privacy settings
FormSuggest - disables AutoComplete for forms
FormSuggest Passwords - prevents Prompt me to save password from being
displayed
Connwiz Admin Lock - disables the Internet Connection Wizard
Settings - prevents any changes to Temporary Internet Files
ResetWebSettings - disables the Reset web Setting button
Restart Internet Explorer for the changes to take effect.
http://www.winguides.com/registry/display.php/797/
Use System-based Internet Restrictions (All Windows)
Internet restrictions are normally dynamically loaded for each user,
therefore settings for one user do not affect the settings of another. This
tweak forces Windows to use the local machine settings rather than those of
the current user.
http://www.winguides.com/registry/display.php/1133/
Repair the Taskbar (All Windows)
If your taskbar has disappeared from the desktop or becomes hidden when you
move your cursor near, it may be due to a corrupt registry key.
http://www.winguides.com/registry/display.php/277/