did you check in the most obvious place hp.com? it basically says hp drivers are updated through windows updates OR it's own recovery app. i don't think i can link to this page so i will post it here:
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drivers and downloads for
hp pavilion 512c desktop PC (US/CAN)
HP Pavilion Desktop PCs - Not Finding Your Software and Drivers?
HP publishes updates to Pavilion Desktop software and drivers. If no updates are available, you already have the latest software and drivers from HP on your system.
HP Pavilion systems with Windows XP do not come with recovery CDs. Use the following steps to restore a software application or driver in Windows XP:
Click Start, All Programs, HP Tools, and then Application Recovery.
In the Recovery window, select either Drivers or Applications as desired and click Next.
Select the software driver or application that is to be reinstalled and click Next.
The driver or application will automatically be installed. Some programs will take longer to install than others.
You may also obtain updated software and drivers from the manufacturer of the specific software or hardware, or by using Windows Update.
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