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:
• Retrieving Information from Computers Belonging to an Active Directory OU
• How to Erase a Hard Disk Drive Permanently
• Uninstall OneNote from Windows 10
• Use Free Autoruns Utility to Disable Unnecessary Startup Programs
• Script to Display the Processes Running on a Computer
• Windows PC Performance Troubleshooting and Optimisation
• Set Up Parental Controls
• Create a Windows 7 System Repair Disc
• Windows 7 Tweaks
• Disable Long Filenames to Improve Window's Performance