Whoa, you're not going to get very far if you try to close Explorer and Systray
Let's start a fight. The AMD K6 processor is not going to perform well. If you think it does perform well, then you haven't had it side by side with a cheapo Intel processor....or you're not using too many DX effects (esp. reverb). You might be able to upgrade to a K6-2 depending on your mobo. It'd be cheap and would provide a bit more performance. Unfortunately that's your only option without replacing the mobo.
BUT, you should be getting more than one track!
There is a lot more to your computer than the processor. First and foremost, your hard drive and memory. The hard drive will really make a BIG difference. If your hard drive is pre-UDMA/33 then good luck. You'll also need enough memory to keep windows and your application happy and minimize swapping, though the multitracking program you are using might write directly to the disk (e.g. overkill on the memory won't help). I've found 32MB to be fine, and going to 64 helped...but more than 64 didn't seem to help much.
BUT, you should STILL be getting more than one track.
Check and recheck all of your drivers. Make sure they are up to date...especially if you have a cheap soundcard.
Finally, how old is your windows installation and what version of Windows are you using? It may sound ridiculous, but Windows95/98 loves to be reinstalled. I used to use Windows98 for recording and over time it started getting slower...and slower...until I was only getting 4 tracks or something. I said screw it, installed NT4 and everything has been peachy since.
Here's a groovy trick to free up some memory. Open up \Windows\system.ini and edit the line:
shell=Explorer.exe
to read
shell=Progman.exe
Remember Windows3.1? Have fun.
Slackmaster 2000