can't boot from live usb lubuntu 14.04 LTS

[Linda]

I am trying to boot an old HP Pavillion a1230 n with an AMD 
Alhlon 64 processor and 2 GB RAM from a live usb  with a 
view to intstalling lubuntu on the machine
When I boot it hangs on the splash screen. I tried booting 
with quiet splash removed and I have a infinite loop of the 
following error message

ata1.00 status: {DRDY}
ata1.00 hard resetting link
             configured for UDMA/33
             Device reported invalid CHS sector 0
             EH complete
             lost interrupt
             exception Emask 0x0 SAct 0x0 action 0x6 frozen
             failed command READ DMA

There were a few other lines but these seems to give the 
gist of what is going on.  Any ideas on how I can get this 
to work.
                    Thanks
                     Linda