Hi, I have this ISO but is corrupted (5 GB in size) I don't want to download the thing again (took me over a week), so I wrote a powershell script (see the attachment md5blocks.ps1.txt) that prints out the MD5 checksums for each consecutive 20MB blocks (see the attachment output.txt). Each line has three fields: (1) start offset, (2) end offset, (3) MD5 checksum for block from offset (1) to (2). For example, 0000000000 0019999999 70a29568cf9a1735379d04fd4af25bbd 0020000000 0039999999 28831129846a6d8f459ca039441cdd3c say: 1. The block from offset 0 to 19999999 has the MD5 70a29568cf9a1735379d04fd4af25bbd. 2. The block from offset 20000000 to 39999999 has the MD5 28831129846a6d8f459ca039441cdd3c. I have attached the script as a text file "md5blocks.ps1.txt". If you can help, can you rename it to "md5blocks.ps1" and execute it against a good, uncorrupted copy of the mentioned iso: And paste the output or upload an attachment here. Then I can compare with mine to see which parts are corrupted. The script is basically a short piece of C# code that reads the iso in 20MB blocks, computes the md5 for each block and prints it. Nothing more. Thank you for your help.