suddenly, cannot print, xp

check for bangs in Device Manager. SP1 lost from add remove programs is maybe separate issue...do not necessarily reinstall it to fix usb problem. it sounds like hardware failed...

First I would recommend to run the latest virus Checker. If no virus is found try to delete your printer in Control Panel>printers, reboot your system and plug and play should pickup your printer with the old drivers and install it. I normaly download the latest printer drivers and reinstall with new drivers.

If you did an upgrade you would need to download additional drivers for xp. If you send me the models of the devices you have I will send you the links to the pages to download the drivers you need. Also do a surface scan and a defrag and a virus scan.

How do you know you lost service pack 1? If you open system properties the "general tab" will show what version of Windows and SP1 if installed. This to me is the type of problem I would have to resolve before anything else. If you have virus software do a full system scan. There should be a folder where the service pack backup files were saved mine is located in the folder; C:\WINDOWS\$NtServicePackUninstall$

Since nothing is working on USB I wouldn't worry too much about the specific devices. Check in device manager to make sure there isn't reported problems with USB.

Uninstall the printer and camera drivers and related software. Remove all USB ports and controllers in device manager. Get out the motherboard driver disk and reinstall the Usb devices.

Get the disks and users manuals for the printer and camera and follow the instructions to perform the reinstall of those. Most Usb devices are not connected until prompted to do so durring setup routine.