Hello,
when i tried to install TC (running it from the USB flash drive), i selected my HDD partition (sda1) as a destination.
and as a source core.gz file that i found in /mnt/sdb***/boot (by the way this is very inconvenient, because not every noob knows he need to find that file here!) and then proceed and it stopped with error like that it is unable to mound my USB drive.