There are three ways to change the default PDF opening method to your desired application: through File Explorer, System Settings, or Control Panel. First, you can right-click on any PDF file and select "Open with" and check "Always use this app"; secondly, enter the "Default Application" setting through [Win I] and specify a program for .pdf; you can also manually associate it through the "Default Program" function of the control panel. If it is still changed after setting it, you need to check whether the security software has reset the association, and make sure that the PDF reader's own settings have been set to default to avoid conflicts between multiple PDF software and lead to unstable association.

The right-click menu is stuck due to registry redundancy or software conflicts. It is necessary to clean up the ContextMenuHandlers items, delete non-New sub-items, use the search function to check the Directory path and delete redundant items, uninstall third-party software such as 360 or NVIDIA, and update the graphics card Bluetooth driver to solve the problem.

Windows 10 right-click menu can be managed through third-party tools, registry editing, or command line. Firstly, it is recommended to use visual tools such as "Windows Right-click Menu Management Assistant" to add or delete menu items after running as an administrator; secondly, you can manually edit the registry, create a new shell item under the relevant path of HKEY_CLASSES_ROOT and set the command subkey to point to the target program. You need to back up the registry before operation; finally, you can use the open source tool ContextMenuManager to batch manage menu items through command line list, disable, enable and other parameters, which is suitable for advanced users.

Windows 11 can enable the taskbar clock to display seconds through settings, registry, command line, or third-party tools. 1. Turn it on in settings: Go to Personalization → Taskbar → Taskbar Behavior and turn on "Show seconds in system tray clock"; 2. Registry modification: Create a new DWORD value ShowSecondsInSystemClock under HKEY_CURRENT_USER\SOFTWARE\Microsoft\Windows\CurrentVersion\Explorer\Advanced and set it to 1; 3. Command line execution: Run PowerShell as an administrator and enter regaddHKCU\Softw

First, check the space occupied by the C drive restore point through the System Protection tab in the system properties. Secondly, use the PowerShell command vssadminlistshadowstorage to obtain the total volume shadow copy occupation. Finally, check the SystemRestore task frequency through the Task Scheduler to evaluate the storage impact.

1. You can view and adjust Windows 8 background services by running services.msc, Task Manager, Computer Management and Command Prompt. The operations are applicable to quick access, resource monitoring, comprehensive configuration and batch query scenarios.

You can cast mobile videos to your computer through QQ browser cross-screen traversal, Miracast mirroring or third-party software. First, make sure the device is connected to the same WiFi, use the same QQ account to log in to the QQ browser on both the phone and the computer, click the "Cross-Screen Travel" button on the video playback page and select the target computer to complete the screencasting; if the computer supports Miracast, you can click "Screen Mirroring" in the phone control center to select the computer name to connect; you can also scan the QR code through third-party software such as ApowerMirror to achieve high-definition transmission.

1. Disable non-essential startup items through Task Manager to improve boot speed and system response; 2. Adjust visual effects to optimal performance in system properties to reduce graphics resource usage; 3. Use disk cleanup tools to delete temporary files and perform defragmentation to improve hard drive efficiency; 4. Turn off Windows Update automatic checking and delivery optimization functions in Update and Security to reduce background resource usage; 5. Select a high-performance power plan and set the minimum processor status to 100% to ensure full release of hardware performance.