I was an IT guy for many years.
I haven't seen one in a long time, especially since floppy drives went extinct, but a CRC error occurs when data can't be read - in this case, what can't be read is a file named Data2.cab, which is a compressed installation file. In the case of CDs\DVDs, CRC errors are usually due to a defective or dirty disk or CD\DVD drive (or even a drive that's too sensitive to scratches on the media). If you were using a downloaded installer, it can be caused by a corrupt or incomplete download.
In short, try cleaning both the disk and the drive. If that doesn't work, try an different DVD drive, and if THAT doesn't work, the only option left is that the disk is pooched...