modding an XBoc is Illegal, and NGEmu doesn't really support that type of stuff but yeah there are emulator for XBoc and you can also install windows if you want but it all pretty pointless if your comp is better than your boc.
In the US Modchips are illegal under the DMCA. They are illegal because they allow to circumvent (get around) the copy protection on the PS2 Xboc. There's a way around this and that is if you get a Modchip this is blank, and then you flash them with the files yourself.
Sorry for getting off topic but I did a whole project on thid stuff.