Because Windows 10 operating system's search function (which Cortana digital assistant controls) uses Bing search engine which pushes Windows app store products and tries to trick you into signing up for Microsoft's OneDrive, you may not want to upgrade to Windows 10 (even though it's a free upgrade).
The KB3035583 update installs the "Windows 10 downloader". Here's how to remove that update.
1. In Control Panel small icon mode, click on the Windows Update icon.
2. In the lower-left corner of the Windows Update page, click on Installed Updates, and allow Windows time to update the list.
3. When the updates list has completed updating, enter KB3035583 in the upper-right corner Search box, and allow Windows time to perform the search.
4. If KB3035583 is listed in the results, select it and click on Uninstall an update, when the confirmation message box appears, click on the [Yes] button.
The KB3035583 update also adds a ⁄Windows⁄System32⁄GWX folder to the system. The folder contains GWX.exe which has the description "Get Windows 10". You should delete that folder.
More Windows Administration Information:
• The Security and Maintenance of Messages in Outlook Express
• Windows PC Performance Troubleshooting and Optimisation
• Use Free Autoruns Utility to Disable Unnecessary Startup Programs
• How to Setup a VPN Between Two Computers
• How to Harden a Server
• How to Reset Windows 7 Password
• Create a Shortcut to Windows 10 Services Management Console
• Basic Functions of Microsoft Active Directory
• Disable Annoying 'Get Windows 10' Message
• Configuring Windows as a NTP (Network Time Protocol) Server