If your PC or laptop is using Windows 7 and you notice slow data transfer rate when you attempt to copy data of 10 GB or larger onto a blu-ray disc, there is a good news for you. This issue has been addressed by Microsoft and they have come up with a hotfix that remedies the problem. When it is said that the rate is slow, it is extremely slow that the copying process almost comes to a crawl.
According to Microsoft source, this issue is due to the error checking that takes place in Universal Disc File System driver (Udfs.sys) file.
The hotfix is not included in Windows 7 service pack 1; so you need to manually download and update the hotfix. It is advisable to you to apply the hotfix by yourself even though Microsoft has promised to include the hotfix into Service Pack 2 (SP2) because it will take several months before we could see the official release of SP2. You can go the Microsoft’s official page through the link at the end of this post.