How do I completely reset my computer?

I don't mean restart or reset back to a previous date. I mean reset back to original factory settings.

No, I do have spyware, viruses, or trojans so don't give me links to security programs.

I just want to completely rid my computer of all previously installed and downloaded files. If anyone has a simple, safe way to do this please help me out.

Thanks in advance = )

How do I completely reset my computer?pc security

You need the recovery disk that came with the computer. Pop that in and follow the instructions.

How do I completely reset my computer?symantic

Most e-machines come with a recvery disk that is easy to use. but if you have another brand, then reinstall the same Operating system that you have now, or try and find one that is compatible with youre computer's hardware configuration.
depends on which brand computer you are using..each brand has a different setting or may be your computer does not support it.

You have to read yur computer manuel for it or else let us know what brand it is
take the operating system disk and reformat the whole drive,most OS disks automatically put the settings back to factory defaults
I know that some older pre-05' computers allow you to do a deconstructive restore via a program others allow you to boot a recovery mini-os.