[Knippschild]

I believe it was previously mentioned, but hosting your own server on a home computer is very risky.

While technically, it would be considered illegal (if it's in a contract), there would most likely be no legal action taken against you. The way an ISP can detect if you are running an open website is by monitoring port usage. If they see incoming connections on common web (HTTP, FTP, etc) ports such as 80 and now even 81, they will usually shuffle your IP. This more of a hassle because you'd have to change your domain to reflect the change. After continued website host-age, the ISP may eventually discontinue service or append fees to your account.

Also, even if it is legal, it's most likely going to be lagged due to it most likely being on Cable/DSL.

If you host any kind of server, it should be fairly dedicated to that application otherwise you can use resources and cause some sort of slowdown elsewhere on the client side while browsing.

Your home computer will also be vulnerable to attacks, no doubt.. and running an open server on windows is a bad idea in itself (no offense, microsoft) as that opens you to windows' many vulnerabilities and exploits. Most server farms run a flavor of linux (RedHat, Ubuntu (not as much), Debian, FreeBSD, etc) which most server software (HTTPd, IRCd, etc) are meant for.