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:
• How to Check Your PCs TPM
• What is Windows Aero and Mouse Gestures?
• Create a Shortcut to Windows 10 Services Management Console
• Disable Annoying 'Get Windows 10' Message
• Internet Connection Sharing in Windows XP
• Planning a Backup and Restoration of Files for Disaster Recovery
• Make Windows 10 File Explorer Open to This PC instead of Quick Access
• Windows Event Logs for Maintaining or Troubleshooting Your PC
• DOS Tasklist and Taskkill Commands
• Use the HOSTS File to Block Web Sites