I have a Windows 2000 Professional RTM ISO with the following info: Size: 378.122.240 bytes SHA1: a64fc69b95e760e880534049a56bcc1455cb7fd6 CRC: 32b038b5 The ISO seems untouched, but shouldn't its CRC be FFFFFFFF? All files/folders have the same date/time, it was created with cdimage 2.27, it has AutoCRC at 0xA17F0 and at the end. I copied the data up to 0xA17FF to a new file and it has CRC FFFFFFFF, so the header is ok. I assume the problem must be a corrupt byte somewhere, but i don't have anything to compare it to. If someone has this ISO with the correct CRC, could you spare a few minutes to create a PAR file with a few recovery blocks? I'm sure that will fix it.