What can I make out of a Old Pentium D desktop?

Hello homelabbers,

Recently I came into possession of an old Desktop PC. Its configuration is,

• Pentium D 820, 2.8 GHz dual Pentium 4 core processor, supports 64 bit.
• 512 DDR 333 memory
• 90GB HDD
• no graphics card
• 3 PCI and 1 AGP slot

I was planning to put a ethernet card and use it as a router. It was to theown as garbage. Is what I am planning feasible or a good idea. Or it would be better as trash.