I can cut down a tree, mill it into lumber, and build a house out of it. It does not follow from this that a tree is a house. Once a tree is "treated and arranged" in the particular way that turns it into a house it is no longer a tree. Likewise, once beach sand is "treated and arranged" in the particular way required to make it compute, it isn't beach sand any more.

> The ability to compute is present in all matter.

No, it isn't. If you think it is, tell me how to build a computer out of a single hydrogen atom.