Take the 2-minute tour ×
Super User is a question and answer site for computer enthusiasts and power users. It's 100% free, no registration required.

Okay, so I downloaded Windows 8 Preview twice, once from my Bulgarian computer and once from my American NAS becasue the SHA1 Sum didn't match for the Bulgarian download. I redownloaded it twice from Bulgaria and both times it got the same SHA1 and MD5 sums. Ironically, I searched for the SHA1 sum on Google and two other people had this exact SHA1 sum. I'm looking for an explanation of this.

  • Was one copy of Microsoft's iso in their CDN corrupted?
  • Is the two byte change a logical change for a corruption?
  • Is it something else, like an corruption from a 3rd party?
  • How have 3 people gotten the same corrupted file?
  • How did I get the same corrupted file 3 times in Bulgaria and the right one when I got it from the states?

The two posts seemed like they were not from an English speaking country, maybe Europe for both of them. They both also happened on March 1st, but I don't remember when mine was. I bet it was about that time because one of them hadn't been indexed by Google when I first ran into this problem. That would support the theory that one copy on the CDN being corrupted and it was just the nearest to the three of us.

Windows8-ConsumerPreview-64bit-English.iso SHA1 sums:

1288519c5035bcac83cbfa23a33038ccf5522749 from USA

bdb76fbdcadb570d9d1a7955c7dd582f7ff585c8 from Bulgaria

Here are the actual differing bits from vbindiff:

USA (good SHA1):

0C6E 76A0: 00 00 C2 02 00 00 00 00 00 01 00 01 00 00 00 F6 ........ ........

Bulgaria (bad SHA1):

0C6E 76A0: 00 00 C2 02 00 00 00 00 00 01 00 5E 02 00 00 F6 ........ ...^....

share|improve this question

1 Answer 1

Not an answer per se, but I downloaded this in Redmond, WA (I can literally see Microsoft campus from my desk) and I have the same SHA-1 as your Bulgaria bits:

SHA1(Windows8-ConsumerPreview-64bit-English.iso)= bdb76fbdcadb570d9d1a7955c7dd582f7ff585c8

My first thought was maybe you had two different language versions and the only difference is which value is in some setup config? Otherwise it seems suspicious that it would only differ by a few bits. Are you considering the USA version the bad one because of the SHA-1 they listed?

I was trying to determine if the latest version online is the one I have or not so I was comparing SHA-1s. Googling for my SHA-1 brought up this SU question. It looks like current "Windows8-ReleasePreview-64bit-English.iso" is different from mine.

Edit: I just downloaded "Windows8-ReleasePreview-64bit-English.iso" and their download page says

Sha 1 hash — 0xD76AD96773615E8C504F63564AF749469CFCCD57

Yet I get this:

SHA1(Windows8-ReleasePreview-64bit-English.iso)= 57f3f4cd26b23252942da2265991f71fbfb10ae6

Oh well.

share|improve this answer

Your Answer


By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.