Unable to complete file download using IE 11, Firefox 31.0 or Chrome

Equipment:
Refurbed HP Compaq 8000 Elite
Intel Core2 Duo x 2
12 GB DDR3
Radeon HD 5450 graphics

I recently had a boot sector failure on my hard drive. I inserted a reformated on hand 320 GB drive. I then reinstalled Windows 7 Professional SP1 and proceded to rebuild my files and programs from back up files. Where I did not have a copy of a file to reinstall, getting that file from the Internet has been a NIGHTMARE! Some files download the first time. But most files seem to hang when 95-98% of the download is complete. After a while the download will signal complete but installation fails due to file corruption. Multiple retries using different browsers and multiple DL locations yield the same results. Rarely a DL stub will succeed where a full file DL failed. The problem is browser independent occuring with Firefox 31.0, Google Chrome, and IE 11. I do not know if this is related or not but Adobe Flash also crashes every time it is called. Viewing a complete video is impossible. Any ideas as to cause and fix?

I finally decided I just had a bad install of Windows 7. I did a re-install on a freshly formatted one Terabyte hard drive. Everything works!