When I download games, Archive manager comes up with error.

If the file ends in ".exe" (or ".EXE"), don't try to open it with the Archive Manager. A file ending with .exe/.EXE is usually a Windows executable. To run Windows executables on Ubuntu, you need to have Wine installed. To install Wine, go to Applications > Ubuntu Software Center, type "wine" (without the quotes) into the search box at the upper-right corner of the window; when Wine Microsoft Windows Compatibility Layer comes up, click on it and click Install. Once Wine is installed, right-click on the .exe file and click "Wine Windows Program Loader". If that fails, try right-clicking on the file and clicking Properties, click the Permissions tab, check the box that says, "Allow executing file as program", click Close, and try again. Please note that not all Windows games can be run with Wine, and some of the ones that can be run requires that you perform some actions manually to get them to run; you can search for information on running specific windows games and apps at http://appdb.winehq.org/objectManager.php?sClass=application&sTitle=Browse%20Applications&sOrderBy=appName&bAscending=true.

If the file ends like .7z, then go to Applications > Ubuntu Software Center, type "p7zip-full" (without the quotes) into the search box at the upper-right corner of the window. A single search result should appear, called p7zip ("7zip compression/uncompression tool"). Click on that and click Install. (If you see a button labeled Remove instead of Install, that means it's already installed. Don't click Remove!) Then try opening the file with the Archive Manager again.

Similarly, if the file ends like .rar, then go to Applications > Ubuntu Software Center, type "unrar-free" (without the quotes) into the search box at the upper-right corner of the window, click on "Unarchiver for .rar files", click Install, and after that's installed try opening the file with the Archive Manager again.

If the file does not end like .exe, .7z, or .rar, or it does but the above solutions don't work, then you'll need to provide more information.

Does the Archive Manager just say "error", or is there an actual error message? Assuming there is an error message, please post the error message in its entirety.

The archive you downloaded probably ends with a dot (".") followed by 2-4 characters (e.g., .zip, .rar, .7z, .lzma). If this is not the case, please let me know. If this is the case, please specify what those characters are. If possible, please provide the complete name of the file. (You might not be able/willing to provide the complete name of the file. For example, if you have received this game as part of a closed beta, your license agreement or NDA might prohibit you from revealing this information. But providing this information is probably fine.)

Assuming that the download source is public and you believe I could download the game (from the same source) without violating United States copyright laws, please post the link where you downloaded the game (or, if you didn't get it from the web, describe how you did get it).

Finally, open a Terminal window (Applications > Accessories > Terminal), type "file " (without the quotes, but with the space at the end), drag the file into the Terminal window (this pastes its full path), and press enter. Then select all the text from the Terminal window (Edit > Select All), copy it to the clipboard (Edit > Copy), and paste it here. That text will provide additional information about the file that should be useful in attempting to open it.