Product key for office 2007

If your pc came with office 2007 on it and you brother installed another version of office 2007 then it's likely to have overwritten the existing version.
If you go into the programs menu and you can only see one entry for microsoft office then this is what's happened so uninstalling will remove the lot.
Don't dispair, you can get open office which is microsoft compatible and is free. OK, it's a little different and some people don't like it because driving it is a little different but it's now a very good alternative.

http://www.openoffice.org/

No. If the other version was uninstalled during the 2007 install, then it won't be available.

It is possible to have both installed at the same time though, so first check to find the previous version. If it is still installed, then it will stay installed after you uninstall 2007