prompter: What happens of i delete all file located in system32 in windows OS ?.

assistant: Deleting all the files located in the System32 folder in a Windows operating system can cause serious problems, as this folder contains essential files and libraries that the system needs to function properly. Deleting these files could make the system unstable or even render it completely inoperable, resulting in a potentially irreparable system failure. Therefore, it is strongly advised not to delete any files from the System32 folder unless you are absolutely certain of what you are doing and have a good reason to do so.

prompter: Then why did people online suggested I should delete it to make my game run faster ?

assistant: "Delete System32" and "Alt+F4" are usually said by internet trolls and people meaning to be humorous, and should not be taken seriously.

assistant: This is the same reason many suggest to press `ALT + F4` to perform certain actions in video games. 
They are trolling and find it funny if others are suffering.

assistant: It's a joke that started on 4chan's /g/ board (although it was probably in use on other, smaller forums before that), where deleting system32 would fix whatever problem the poster was experiencing.

assistant: If files and directories were deleted under System32, Windows Operating System would no longer be able to functions without it's required programs, kernel, drivers, registry, and configurations. Therefore it is generally advised that you do not delete System32 under any circumstances.

prompter: Is there a way to recover my machine if I deleted System32 by accident?

assistant: deleting all file from C:Windows System32 should be avoided since it might seriously disrupt the system. Important Windows system files are included in System32, and removing them may make the system unstable, corrupt, or prevent it from starting. It is advised to only remove files from System32 if you are certain that doing so won't result in problems and that you know exactly what you're doing.

prompter: Is there any way to recover from having done this? I ask because a close friend has somehow mistakenly done this in an attempt to remove a virus. They haven't turned it off yet and are sitting next to me right now, it's an older laptop but there are files on it that are precious to them.

assistant: It seems like the computer is still powered on and operational, is this the case?

Assuming the computer is still operational, it would be highly advised to use an external storage device such as a USB flashdrive or cloud storage provider to begin copying over the any critical/important data off the computer's local storage. Besides possible system instability due to some files missing, any potential malware could attempt to encrypt or delete files after some time so their backup is of the utmost importance.

Windows typically prevents a user from deleting those files, but if in some rare edge case this was completed using the typical delete methods, and the computer is still running, then it is possible that the "Deleted" files have just been moved to the Recycling Bin. This would allow you to open the Recycling bin and easily restore all the files using the tool at the top of File Explorer.

Hopefully with the computer still running this is able to help you mitigate the potential for data loss. If there are other complication with the computer or it is unresponsive I can assist further.

assistant: In an order that seems right to you. You should accomplish two things. You should attempt to recover the files that you have deleted and you should attempt to backup the files that are important. When that fails with a system hang. you should attempt recovery with a second computer. If the files are stored on a separate partition, the user files should be insulated from Operating System troubles. It is advisable to have a second computer handy. Mount the affected computer's hard drive into a External drive enclosure and plug it into the USB port of the second computer. All files and directory structure should be visible. After creating a backup, its always good to remember that one backup is none.

assistant: Windows keeps user files in a separate folder than system32, so they are likely safe. The easiest way to recover them would be to downlead a windows operating system to a thumb stick and booting the computer into the operating system contained on the thumb stick to start a recovery of the windows computer. It should allow for a restoration of the computer and all personal files but not necessarily the apps that were located in system32. You can download this using Microsoft's official recovery tool, which can be downloaded on the website link https://support.microsoft.com/en-us/windows/windows-device-recovery-tool-faq-2b186f06-7178-ed11-4cb6-5ed437f0855b. Note that this will require you to start your computer into its BIOS and selecting the recovery tool to be booted. Online tutorials on youtube can show how this is done. Using a tool that restores deleted files can also sometimes work but is not as reliable. In the future files can be backed up to cloud storage if they are important, and there are free options such as microsoft onedrive or google drive.  Deleting system32 in the future is also not recommended as it will similarly result in the failure of the windows computer. 
Although the deletion of important files in windows is a serious event, using the right tools and approaches can help recover important files. If the above approaches do not work, it is recommended to contact a professional organization in computer data recovery.