X5495 Printer Driver From Lexmark Site Not Installing Correctly, Windows Vista .

Hi, I have a Lexmark X5495 and Windows Vista family version on a desktop. The printer is connected via usb, and always worked perfectly, pre-virus, but then I got a trojan or some other virus and had to re-install all the non-factory software, including the printer driver. The computer is clean, I've scanned it thoroughly with AVG. I downloaded the printer driver directly from the Lexmark site. I have downloaded, uninstalled and re-downloaded it twice now, and each time I get the same problem. At the end of the installation process, vista tells me that "the driver has not installed correctly" and that the second element, I think called configuration control(?) was displaced or removed by user or something similar. I am not aware of having clicked on anything of the kind, just followed the installation procedure page by page. Vista recognises that the Lexmark is connected when I re-boot, but comes up with a window telling me that there is no driver for this new hardware. It does not "see" the printer in the control panel, however, nor is the X5495 listed as a printer in the "add printer" drop-down list in the control panel printer section. In the Productivity suite, if I click on "printer status and maintenance", it tells me that "the item that you requested requires a product that has been moved or deleted". The driver shows in the programs list of control panel but something is obviously not right. Can anyone help, please? I am at the outer limits of my minimal technical ability and have no idea how to fix this. And I need to use the printer urgently to scan children's drawings for emailing to waiting, seriously ill grandparents... Thank you in advance for any help.