Compaq n600c worth upgrading?

I recently got an older Compaq n600c for about $50, which my wife is going to use for her accounting office. Realizing that Quickbooks and Lacerte don’t exactly have hefty hardware requirements, is it worth:
1) Upgrading the RAM from its current 768MB to 1GB?
2) Upgrading the OS to Windows 7 from XP (which would require the RAM upgrade first)

This machine is factory spec other than an already upgraded RAM.