Spybot, do not use this tool if you use a DAW, Spybot could change/block elemental registry settings, that are needed. Never use an automatic registry cleaner.
256 Mode could break your system down, especially if you have a modern Graphic card.
With a Saffire LE you will have issues with 5ms latency, if you set it higher, still got problems?
Do not kill any process in your Taskmanager, some are in need for a proper system usage.
My recommendation is a fresh install of Windows 7, do not use the Jbridge because it will need more CPU power. If you want to use Cubase for a live setup, just use the 32-Bit version.
Then use the DPC latency checker tool in order to sort out the issue.