Up until Last summer, I was running SE4 on this machine:
333 MHz Pentium III
384 MBs SDRAM (always nice having more RAM than CPU clock cycles

)
8 MB ATI Rage Pro
~1.5 GB Hard Drive space over 2 drives
Some random MB that I do not remember...
Windows 98 (2000 towards the end of its lifespan)
So don't feel so bad.
That computer was sort of scrapped for parts, later to be semi rebuilt, and it isn't currently in working order.

Now, I have:
2.0 GHz Pentium IV
512 MB DDR or RD RAM (I forget which)
64 MB nVidia GeForce 4 MX 440
100 GB Hard Drive w/8 MB Cache
ASUS MB
Currently running XP Pro on it, was running 2000 until a few months back
Just a minor upgrade.
Both computers were put together by hand, by me.