Download, on a separate computer, the free Firefox browser. Transfer it using a flash drive, then install it and see if Firefox downloads things correctly.
http://www.mozilla.com/en-US/firefox/personal.html
If it doesn't, then try downloading, installing, updating, and running a full system scan with the free Malwarebytes program from the link below:
Malwarebytes Antimalware
Hope this helps.
Grif
I have been having trouble with down loads , they all stop at 99% and will not complete the down load, what is wrong?
software? hardware? internet connection? I do not have a clue what to do.
Chuck

Chowhound
Comic Vine
GameFAQs
GameSpot
Giant Bomb
TechRepublic