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:
• Disable Unnecessary Background Apps
• Check Your Version of PowerShell
• Defend Your Business with a Firewall
• How to Erase a Hard Disk Drive Permanently
• Understanding Windows 7 Security Center
• PC Technician's Guide to Providing Telephone Support
• How to Transfer a Large Amount of Data Between Two Windows 10 Computers
• What Are Windows Server Containers?
• Turn Off Windows 10 Snap and Shake
• Environment variables in PowerShell