The specified file is missing or corrupted, or possibly the network has a connection problem.
Get another clean copy of the installation file. If downloading the file, delete the existing download and re-download a fresh copy.
If the file reside on a network, try copying the file to your local system first, and then use the file locally rather than over the network.
Fix the network connection. Assuming the physical or wireless connection is working, have Windows attempt a repair:
For Windows 7:
For Windows Vista:
For Windows XP:
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