my computer shows black screen , if you save wallpaper it disapper after a time and ther are some word at the right down corner of the screen says 'this type of window is not gunuine'

As the comment suggests, it isn't a genuine version of Windows.

It has been known for some scam viruses to trick you into thinking this and providing you with a fake link to 'purchase' a genuine copy of Windows or it is in fact, a fake version.

Where did you purchase the computer from, how long ago or did you install the OS yourself?

It means your Operating system is not genuine,,, try to purchase genuine OS...to avoid seeing this type of window is not gunuine'..

hi gilbert.patrick.58 meaning that you have to activate your windows with a serial or product key provided to when you bought the OS hope this helps

you'll need to buy and activate a license as it seems you have either installed a trial version or pirated version of the OS

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