I don't know which checkbox to set for downloading Windows 7: x86 oder x64 or both? I Have Win 7 Home x64, but on my harddisk there is a folder named "Program files (x86)". Thanks for any help.
The checkbox is for the architecture of the operating system, in your case x64. "Program files (x86)" folder is the standard installation path for 32Bit Software while there's another named "Program files" which is used for 64Bit Software.
Microsoft update catalog: http://catalog.update.microsoft.com/v7/site/ Windows Install media download: https://support.microsoft.com/en-us/help/15088/windows-create-installation-media