Is there a reason for 7.6.1, as opposed to 8.x? The 3400c is much happier with 8.1 (and better still with 8.6), owing to the diminished need for emulation. Video playback, for example, is much poorer with 7.6.1 than with 8.1, and poorer still than playback with 8.6, on a 3400c.

If you're still in need of 7.6.1, PM me. I might be able to help you locate a suitable version for the 3400c.