HP Deskjet 6122 Color Inkjet Printer - Manual (Page 120)

minimum system requirements
Your computer must meet the following minimum requirements to use the printer:
Microsoft Windows XP
Minimum Processor Speed: Pentium 233 MHz
Required RAM: 128 MB
Required Free Hard Disk Space: 40 MB*
Microsoft Windows NT 4.0 (SP 6 or higher) or 2000
Minimum Processor Speed: Pentium 133 MHz
Required RAM: 64 MB
Required Free Hard Disk Space: 40 MB*
Microsoft Windows 95, 98, or Me
Minimum Processor Speed: Pentium 150 MHz
Required RAM: 32 MB
Required Free Hard Disk Space: 40 MB*
* If you are printing photographs or are printing at 4800 x 1200 Optimized dpi, you
must have a large amount of free hard disk space available.