Is Microsoft SQL Server 2008 necessary and what does it do?

If you don't know what SQL Server is, it's very unlikely that you would need it. This is a database server. That means it's intended to run on a server, and feed data out to an application server somewhere. In basic terms, think of what you see on the page when you visit eBay. Most of that content would be contained within a database of some sort. The eBay web server will talk to the eBay database server to retrieve that data, then display it on your screen.

It is not essential for a computer to run. If you remove it, you probably won't even notice, other than the fact that your computer will run a lot faster without it. "sqlservr.exe" is not needed to run your computer.

I'm going to assume you got this computer second-hand. This is actually an expensive piece of software that doesn't usually end up on computers by accident. Just un-install it and be on your way.

SQL Server is a database server. It is required by certain applications. For example, Windows Live uses Microsoft SQL Server 2005 Compact Edition to store data in. If an application would depend on it and you remove it, the application will no longer work. The file sqlservr.ese is used to start SQL Server.

i take advantage of Microsoft sq. Server 2008 R2 the place I artwork, does the job. There are a pair of human beings who write plenty extra durable stuff than me and their nonetheless applying MIcrosoft sq. Server 2005. i'm no longer fussed shifting over to 2010.

Yes, for some database data loaded from the web resulting from searches you have done.

No, but some web searches will not fully work.

See above.

Nothing, except produce possible error messages when trying to answer some queries.

No but see all above.