U dont need to waste money on a case.
But the 32mb ram has to go. Or at least move it to slot#3 if u got a 3rd slot to make way for a 512 or a 256(I got 1024mb). Make sure its all pc 133 or better. The cpu can be safely clocked to 1.1ghz(if u got enough cooling)and make sure the h-sink and fan are clean with thermal paste between the sink and cpu. My current cpu is a 950mhz celeron 100fsb@1100mhz(the max for my qdi advance 10b board)and no heat problems.
Next: i have a similar ati card that is running at 21%overclock with radeonator at boot:cheers: it works great. Do u need really more drive space? Try getting rid of some junk u don't use first.
Next try tweaking a bit, alot of junk can go and speed can magically appear.
As for sound card, I have:thundering 5.1 cmedia pci card. Drivers appear in windows xp update. Definate improvement and for $25 Canadian, its a steal. Other similar cards cost around $80-100 Canadian.
since u are new to upgrading, its not wise to take big leaps. Since u don't want to waste your cash. email me if u have any questions, some advise can save u hundreds or even thousands