Based on the search results, it appears the request might be referencing two different topics. One relates to modifying the Windows XP operating system interface (installing themes like Royale), and another relates to customizing a vehicle called the Sentinel XS4 in GTA Online. Here are the details for both possibilities: 1. Installing and Customizing Themes on Windows XP
If you are looking to customize an actual Windows XP installation:
Install Modified Themes: To use custom themes (like a “Sentinel” theme) on Windows XP Home/Pro, you often need to patch uxtheme.dll using a third-party tool to allow unsigned visual styles.
Locate Files: Place the theme files (with a .theme extension) into C:\Windows\Resources\Themes.
Apply Theme: Right-click a blank area on your desktop, select Properties, go to the Themes tab, and select the installed theme.
Customize: Select Browse within the theme tab to find specific theme files, then click Apply. 2. Customizing the Ubermacht Sentinel XS4 in GTA Online
If the query is regarding the GTA Online vehicle, based on the video from December 2025, the Ubermacht Sentinel XS4 (priced around $1.4 million) can be customized in a mansion vehicle workshop.
Exterior: Options include armor, brakes, and custom front/rear bumpers.
Performance: Upgrades include engine, exhaust, and racing transmission.
Visuals: Modifications include hood vents, roof boxes, spoiler choices (ducttail to GT wings), and liveries like racing stripes.
Paint: Primary and trim colors can be changed, with options like metallic dark steel for the exterior and shadow silver for the interior.
If you are trying to make a modern Windows 11 system look like XP, users often use RetroBar for the taskbar and OpenShell for the classic start menu. If you want me to, I can: Tell you which uxtheme patcher tools are most common List the best websites to find custom Windows XP themes
Give you a full list of performance upgrades for the Sentinel XS4
Let me know if this was the information you were looking for! How To Change Theme In Windows XP [Tutorial]