Need help downloading and installing

I just had a big problem with my computer (won't go into it) but had to do a complete recovery using the HP recovery console on the space provided on the hard drive. I got my documents back, and a few other things but most of my downloaded programs do not work. Each time I try to download them they won't install. That includes my paid for McAfee and Ad-aware from this site plus my other cleaner programs. It goes through the motions of downloading and just hangs at the end and doesn't install. McAfee says some parts would not installa - try again, and I have tried 7 times. No luck. So with not being able to download any other programs from this site, I know it has to be a setting or something but I don't know what. My security is set at Medium. Can anyone help me with this please. Thank you.