@imnoobda The basic things to test on a wireless mouse are the battery and examining the battery contacts. First remove the battery, then check the battery springs in the compartment for any rust or corrosion. If there is any corrosion, clean the contacts before replacing the battery with a new one. You can also try pairing the mouse via Bluetooth again. Beyond that, there isn't much to repair on a mouse and it is often cheaper to replace the mouse altogether if those steps do not work.

@aqeelraza For the specific model you have listed, the storage is soldered eMMC. There is no way to upgrade the storage. If you need to expand storage for files which are not accessed often eg videos and documents, you can buy an SD card and leave it in the inbuilt reader on the laptop. This will basically function like a USB flash drive that is permanently attached to the system. This workaround is not recommended for use with applications as an SD card will be much slower than onboard storage and will slow down the application noticeably.

@johnnb Does the touchscreen work in the bios for you? This video seems to show it does. Save and exit is on the last page in the bios.

@arz64bs Older Dell laptops have a little pin in the charger tip that makes contact with the charging port to determine wattage. If the pin is bent or missing, the wattage cannot be determined and the battery will not charge. Visually inspect the charger tip and if the tip is bent, carefully bend it back (while the charger is unplugged on both ends and with a non-metal object). If the tip is broken, it usually will be cheaper to buy a used charger than fix it.

@aregadebu Access Device Manager in Windows, find the keyboard under Input Devices and right click and select Uninstall. Do not check the box that says delete the driver software for this device. Then restart the PC. If the keys still don't work upon restarting, you will need a keyboard replacement. You can follow this guide.

@pranitpatharde First thing we need to check is if there is a software problem. Follow this guide to access the diagnostics menu, and select Vibration motor. If it works in the menu, it's a software issue. If it does not, the vibration motor needs replacing, following this guide.

@priyanshuj22511 Most likely your fan is clogged with dust or the thermal paste has dried up. To check this, download and install a program called HWMonitor. You can simulate a load by running a program called Prime95. If your CPU temperature is close to 90 degrees and up, it is a clear sign that there is a thermal problem. Also check if you can hear the laptop's fan when the temperature is high. You can follow this guide to disassemble the laptop and this guide to reapply thermal paste. If the thermal paste replacement does not work, you will need a replacement fan.

@drdineshgarg If you've already reinstalled Windows and tried other software troubleshooting steps, the last thing to do is replace the entire keyboard. It's not unusual for some keys to die as laptops age. You can follow this guide to replace the keyboard.

@basudevmurmu If this is a standard PC motherboard, and you’ve tried both sticks and narrowed it down to the slot, it could be either the CPU memory controller or the motherboard. Unless you have another CPU to swap in, it’ll be hard to narrow down which. If it’s a standard PC motherboard, it isn’t worth performing board level repairs because PC motherboards are really quite cheap, so it may be more worthwhile to replace the board.

@anders12458 If it’s reporting the wrong charging station, the first thing to check is if the vacuum is making proper contact with the charging station. There are two metal pads beneath the vacuum that make contact with the charging station. Take an eraser and clean them of any corrosion and dirt, same for the pads on the charging station. If that doesn’t work, then I’d look at buying a new charging station. Batteries appear to be a different error code 21 so that’s unlikely to be the cause, but you can grab a voltmeter and check if the voltage is lower than they should be.