I have had this problem for awhile now, i cant download anything on my computer.Even attachments from emails. When i try to download , say i press run, it gets to 99% , and then thats it ! I am not so computer literate, my system is windows vistas (dont get me started). Could this be a virus?

Are you getting an error code reported?
It might be worth it to download Anti-malware from www.malwarebytes.com and run a scan just to be sure. You can get if from another internet connected computer and burn it to cd to install it onto your system. Try to update if possible, but run a quick scan and fix any problems it finds...

These sounds like it could be related to Malware. I would suggest three things. A Malware scan, a maintenance cleaning, and checking your start up applications.

I realize that you may need to save these files to a CD or thumb-drive due to the inability to save files when downloading, however these steps must be taken care of in order to establish just what is wrong.

To run a malware scan goto: www.trendmicro.com/housecall

And follow the instructions on the page, let this run, until the results dialogue window pops up, this make take a while. 1-3+ hours. Just let it run, you do not need to attend it once it tells you it is scanning.

For maintenance cleaning, visit this site to download an application called CCleaner
http://www.filehippo.com/download/file/df09062a5bdcfd3a0a0cf31f7117c0cb566fe5b698d89848911da4e434cb72f5/

After these steps.
To adjust what programs you have starting up in the beginning:

Start > Run > Type "MSCONFIG" > Click the Startup Tab then un-check any program entries that you don't need starting up in the beginning. This does not remove them from your computer, just from starting up in the beginning and taking resources in the background. When you need the program, you can simply click on its link in your start menu. It is your choice what you keep and what to remove.

Let us know if you run into any bumps