Outlook signatures are stored in the Windows Registry, a database that stores system and application configuration settings on a Windows-based computer. They are stored in a specific location within the registry that is specific to the version of Outlook that is being used.In Outlook 2010 and later versions, the signatures are stored in the following location in the registry:HKEY_CURRENT_USERSoftwareMicrosoftOffice14.0OutlookSignaturesThe number 14.0 in the registry key path corresponds to the version number of Outlook 2010. For Outlook 2013, the number will be 15.0, and for Outlook 2016, the number will be 16.0.In Outlook 2007 and earlier versions, the signatures are stored in a different location in the registry:HKEY_CURRENT_USERSoftwareMicrosoftWindows NTCurrentVersionWindows Messaging SubsystemProfilesOutlookIt's important to note that modifying or deleting the signatures stored in the registry can cause problems with Outlook, so it's recommended to make a backup of the registry before making any changes.In addition, Outlook signatures can also be stored as individual files on your computer, as well as in an Exchange server or a SharePoint server, depending on the version of Outlook and the organization's setup. These files are usually in the form of .txt, .rtf or .html files, and can be found in the folder where the Outlook signatures are stored.In conclusion, Outlook signatures are stored in the Windows Registry, a specific location within the registry that is specific to the version of Outlook that is being used. The location is different for Outlook 2010 and later versions and for Outlook 2007 and earlier versions. It's important to note that modifying or deleting the signatures stored in the registry can cause problems with Outlook, so it's recommended to make a backup of the registry before making any changes. Additionally, Outlook signatures can also be stored as individual files on your computer, as well as in an Exchange server or a SharePoint server.