STEP7 v5.5+SP4 and WinCC Flexible 2008+SP3 support 64-bit.Just FYI, I decided to keep STEP 7 V5.5 and WinCC 2008 on a separate Virtualbox virtual PC from TIA V13. STEP 7 V5.5 is Windows 7 32-bit, and TIA v13 is Windows 7 64-bit.
Like I said before, I run these on a Windows 7 64-bit, alongside TIA.