MD5 checksum
Users questions: Under the files on the Internet, when using the MD5 checksum, MD5 sum, and available online, as is also normal with decompression. When I copy files to the U disk, then the MD5 checksum of the time when I was changed, I did not make any changes to this file and this file can not actually extract the U-disk, suggesting that the wrong file No more than two types of errors may be
Experts answer: 1 viruses modified the file, but this may be very low 2.u disk has bad sectors or file an exception occurred as a result of data not you go first to the individual, and you almost had that file copy the files as big as the next if u can successfully copy the disk bad sectors that can be Can not then re-copy of the original second successfully copy the file description if this is just an exception if the file is still not the same as you have to consider md5 another reminder md5 virus is not a panacea forged md5 and hash are exactly the same value is reliable