The standard Windows Update service can be buggy on a fresh Windows 7 install. Use the "Windows 7 Convenience Rollup" to jumpstart the update process.
The Internet Archive hosts various "official" disc images uploaded by users. Look for "Retail" or "OEM" versions that haven't been modified. Windows 7 Ultimate 64 Bit Iso
: A major draw for the Ultimate 64-bit edition is its massive memory support—it can handle up to 192 GB of RAM , compared to just 16 GB for Home Premium. Installation Best Practices The standard Windows Update service can be buggy
Some tech sites host mirrors of the original Digital River links (Microsoft's former distribution partner). Windows 7 Ultimate 64 Bit Iso