Bold Text Herehi,Everyone ,please guide me that how i can install MySQL with window 8,problem is that my RAM is of 20 GB and Window8 consume 17GB on RAM .When i install MySQL my pc becomes heavier and slow ,please tell me how i can solve this problem .Thanks

Are you sure windows 8 uses 17GB mem? I doubt it. Also which mysql do you wana install? I suggest use the lighter version and it doesnt take much.
But as a first step i'll suggest try to clear yr rest of the resources so that you get some ram free.

In short, you seem to have installed MySQL so that part of the question looks to be yes.

As to memory, Windows tends to use all available RAM, even for a trivial thing. There are tomes about this on the web and how memory is freed when needed. I think I'll not duplicate that here.

About heavier and slow. Just like packing more in your backpack you will move slower as I add more bricks. Nothing new about that. There are however SQL basic gaffes to avoid. Ever read why SELECT * is a bad thing? (*+bad )

I had to redo that so many times over the years.

Are you sure you mean RAM and not hard disk? Windows 8 occupies that much disk storage, but will run in a far smaller amount of RAM.
Any machine that really has 20 gig of RAM should be able to run MySQL with ease.