cant extract the files from a game downloaded

i need some help i have just downloaded a Nd's game and when i try to open it to extract the files this MSG appears the archive is in a Unknown format or is damaged any one have any ideas why this is

Try redownloading it, its probably a broken download.
Use a download manager if it does it again.

no its doing it with every game i download what's the best download manager to use thankyou

I use freedownload manager but ive heard flashget is good too.http://www.freedownloadmanager.org/download.htm
http://www.flashget.com/en/download.htm

it also says no archive found in selected files and folder and not every game iv downloaded today can be faulty yesterday it was working fine

restart your computer?Then you can use Mega Manager...works for me.
http://static.megaupload.com/megamanager.exe

ok thanks for your help people much appreciated

It happens to me when my mobile broadband loses signal, it stops downloading when its incomplete.
The download manager will just resume it if it stops.If this doesn't cure it, Im out of ideas.

the file is fully downloaded im going to try some of the above thanks anyways

check your winrar version is up to date, unknown format usually means the algorithm version is newer than your version of winrar.

well i did some searching around around n when i finally got to the extraction point is says the disk is copyright protected please remove or use another disk it said that on two games that i have downloaded no of the above work and ill try the update one thanks
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no no think wrong with winery ill try another game then i will defiantly no if it was the file and not wineries problem thanks guys for the help
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does any one no how to take the write protection of a file i have downloaded

is it on your usb?

Right click > Run as administrator