I made Windows 10 look like Vista

You have not converted Windows 10 into Vista; the modified System page indicates that the customization changed resources, registry values, or protected components used to display branding. That is the part most likely to break after servicing. Confirm the operating system with winver and systeminfo, then create a file backup and, if available, a restore point. Use the customization package’s uninstaller first rather than deleting files manually. After rebooting, open an elevated Command Prompt and run DISM.exe /Online /Cleanup-image /Restorehealth, followed by sfc /scannow, to repair Windows components. Install pending updates and verify that Settings, search, Start, and Windows Security still work. If branding remains altered or SFC repeatedly repairs files, restore to a point from before the modification or perform a repair reinstall. Prefer themes, icons, sounds, and cursors that do not patch system binaries. Also remember that normal Windows 10 suppor