I've just spent a frustrating few hours trying to install SQL Server 2012 Business Intelligence as a new instance. I already have SQL Server 2005 Express and SQL Server 2008 Standard installed.
I also have Visual Studio 2010 installed (but not 2012)
The problems come when it gets to installing the development tools - what used to be called BI Dev Studio or BIDS.
The installation fails if it cannot find vs_setup.msi. You are given the opportunity to browse to it. If you point it at the file on the VS 2010 installation DVD, it still grumbles.
One solution (there may be others) which worked for me, is to copy vs.setup.msi to a folder on your local hard drive. You may then be prompted for cab13.cab and most of the subsequent cabs. I ended up copying cabs 13 to 52 inclusive on to the local drive.
The installation proceeds ok after that, although it takes an age to complete.
Some forum posts on this subject, suggest downloading VS 2010 Ultimate from the Microsoft site as a work round. The files for VS 2010 Pro worked ok for me.
I'd be interested to know if you have to go through all this faff, if you have VS 2012 installed.