It has nothing to do with windows 7.
where did you buy the disc? if its from ebay you might have either gotten a conterfeit product or used product that someone else failed to burn.
if you got it from a retail store, take the disc back for refund.
Another thing to look out for, because of how dense blu-ray records, make sure that disc are perfectly clean. absolutly no finger prints, no dust etc....
about the computer check the following:
1) plug it in to onboard SATA controller, don't use PCI or PCI-E SATA expansion cards, often these cards cause problems
2) try replacing the SATA cable, it can go bad sometimes
3) use AHCI mode, google for instructions how to switch, if you don't know the instructions, your computer will not boot.