Problem: Self extracting files reporting corrupt headers

That could mean what it says and that the file you are trying to extract is damaged.
It may also be caused by the CIH virus.

I would suggest that you run an antivirus scan as soon as possible.

You can also go to
They have information on detecting and cleaning up the CIH space filler virus.
This site is run by Symantec, the makers of Norton Antivirus.