epson stylus sx100

Hi all

It keeps changing its status on ink levels i.e some are full then later empty or half full , some times it doesn't register them at all . the print check prints only part of it and does this right on the edge of the paper and i presume the rest is printing off the paper. black has ink comming out of it's nozzle when i squeeze it but doesn't print on paper. I think the ink levels need resetting and the heads centering . Can I uninstall the software an hope vista will plug and play it back? Many thanks