Any of the download mirrors listed on Knoppix's website should be suitable.
thepiratebay.com
Mp3boo.com
I would download linux-Knoppix (An ISO file) make sure it is burnt as a ISO9660 image . This is a live boot program.You can Save the MBR on a working computer and this file can used later overwrite a corrupted one.Get a copy used copy of the book Etermine hacking Knoppix from Amazon.com . The book has live boot CD with it.
itunes
You can download Google Earth safely and for free from Google's official website. Alternatively, you can download it from a website that offers free software downloads, such as Cnet or Softpedia.
iTunes.
NDS Homebrew Hive.
Omniform can be safely downloaded from Nuance's main website. Other websites offer download services as well, but if safety is a real concern it is best to go to Nuance.
Some bootable data recovery programs available for download online include KNOPPIX, Data Rescue, and Wondershare Data Recovery. Some of these are free of charge, and some need to be paid for.
The latest Real Player can be safely downloaded from the Real web site (See links below).
The best way to completely remove any Operating System is to delete the partition that it is on. Your best bet is to download Knoppix and burn that to a CD, then Boot from the CD and find the partitioning tool and delete the partition that the Operating System is on.
Use a boot disc or a Linux LiveCD such as Knoppix