Here is the homepage:

http://www.packardbell.co.uk/pb/en/GB/content/download

This specs provided was complete with a Intel Intel Serial ATA-300 ATA-133 PCI 160 GB Microsoft Windows Vista Home Basic , ATI Radeon Xpress 1100 128 MB 4 MB . The Desktops memory add up to 2048 MB , with standard memory 512 MB , memory installed 533 Mhz DDR2 SDRAM DIMM 240-pin Very low profile PC4300 Compact Flash Type I with 2 Expansion Sockets/Slots.

You can update the graphic, by adding a better graphic card, on the mainboard.
The ram can be upgraded to 2 gb ddr2 ram.
A bigger harddrive, can be added, for more space.
The cpu will be hard to find, it probably have socket 775, but this cpu is not available anymore.
And not all cpu`s will fit the mainboard.

Good luck