ISO burners are free, so is virtual drive software.
Look Here and
also here.I suggest you also take a look at the GP4FAQ, pinned topic this forum. There is a comprehensive guide on installing GP4, you need the v1.02 no-cd exe and the latest version of gpx_patch. If you wish to run a GP4 mod, you need to install CSM-Zaz Tools.
Additionally, a ready to play version of GP4, already burned to an iso file, can be found here
GP4Central.
[
www.mediafire.com] Some say you should click it, you know you want to.
[
www.gp4central.com] <----GP4 Central