HP4500 With Usb Won't Print Under Windows 7

I am working on my nephews laptop which came with Win7 64bit and I installed a usb connected HP4500.all-in-one which was working until recently. It shows under printers as the default and i can use testprint from the properties screen which works fine and prints OK. However, I cannot print with any of the apps like wordpad,acrobat,word 2007 etc. It flashes and disappears and nothing shows up in the print que. I have tried uninstalling and reinstalling with new drivers I pulled from the HP site but still get the same result. Once in a while an HP4400 device shows up which apparently was loaded initially and deleted. I think perhaps a windows update has left something else as the default device