In addition to what Tom has said, in Qimage, Help, click Analyze Current Settings with the Shift key held down. That tells you the biggest file Qimage can handle on your system - it's a Windows thing realated to memory management. A bigger ram does not always help but as yours is only  a nominal 1GB, some more is likely to help.
On my Vista laptop with 2GB ram, the Analyse Settings gives 1544 MB.
Your 24x28 print at 360ppi would give ((360(28+24) x(24x360))x3 = 261MB (the x3 is for R-G-B); at 720 ppi it gives 1045MB. Both of these should be well within Qimage's capability on Vista.
If Qimage did not have enough resources it would tell you before attempting to process.
From this, and you a haven't yet told us if Qimage finishes processing, I assume it did, the data is clogged between the pc and the printer.
I see from your latest post, you are doing the best thing: eliminating the network 
Terry.

Hi
I don't think you should give up on networking the PC, there is no reason why it should not work. Try this (if you haven't already).

Start>Control Panel, then double-click on 'Network and Sharing Center'
Make sure 'Network Discovery' is On, then try 'Connect to a network' or 'Set up a network connection'

To share a folder right-click on it in Explorer (Windows Key + E) and choose 'Share'.

Right-clicking is something some Mac users don't automatically think about, in Windows programs there is always a context-sensitive right-click menu - QI is no exception.



Brian