I am in a position where I might have to prove that I made a certain amount of MB downloads from the Internet including webpages browsed to a court of law. Is there a way of finding this out from Windows Vista Ultimate. If I need to do this in the future is there a way of setting up Ultimate to audit my account to provide a trail of downloads ?
if you are using Internet Explorer, you may be able to recover information of interest to you from index.dat
index.dat is a file used by the Internet Explorer web browser. The index.dat file functions as an active database, which runs as long as a user is logged on in Windows. It functions as a repository of redundant information, such as web URLs, search queries and recently opened files.
you can read the content of index.dat with WinSpy Index.dat Viewer
I am not a lawyer... but from what I know of the Windows auditing sub-system, you're not going to be able to track downloads. The particular browser (IE, Firefox, Safari) you used likely contains history that will show these downloads.
What will probably be of more value is working with your Internet Service Provider (e.g. Comcast, Qwest, Verizon, etc.). They likely will have logs that indicate what sites you were accessing, when and what was transferred.
Regarding the longer-term solution (where you want to be able to prove that you downloaded something) this can be difficult as any system that you own and control can probably have relatively easily faked logs (and may not really be trusted). Using a third-party proxy site that logs these access may help as it shifts the record keeping to someone else.
It completely depends on what you are using to download. Can you give us a bit more information about your environment? What browser(s)? Do you use download managers? What kind of downloads are you talking about? etc...
Your best bet is to set up some kind of logging proxy to run your Internet traffic through. This would record all of your Internet traffic and provide raw data for statistical analysis (sites visited, files downloaded, size of downloads...).
But even then, data in these types of systems are easily forged...