your needs consist of two different things, really; the physical parts like cable and connetors for linking your tapemachine with your PC, and the software for actually recording the sound onto your PC?s hard disk.
The physical bit should be fairly simple. Provided you have some sort of line out on your cassette deck it is only a matter of finding a cable that has a connector that fits that output on one end, and most likely a 3.5mm stereo plug on the other end to go into the "line in" of your PC?s soundcard. Note - though - that you should NOT connect to a "mic in" on your PC, since those inputs are far more sensitive and will only distort a line level input.
Then the matter of recording software. Personally I?ve used Cool Edit for years, and it is just perfect for recording and editing any sort of audio. But there?s such a bewildering array of software available for this particular task that you really have to try out one or two and stick to whatever works for you.
More important is actually learning the strengths and quirks of whatever software you settle for; they all behave slightly differently, and a small amount of effort is needed to get ANY software to do what you want. From the "go online to verfiy something or other" -bit I presume you have used wma-files or tried to use a piece of software that has some option or other set in a "helpful" manner.
The thing is that with the download-hysteria a lot of unpleasant side-effects have emerged. You?re best off to stick to simple recording programs. The more bells and whistles, the more problems and incomprehensibilities. And you definitely do NOT have to pay ANY money to find a good working platform for recording and playback; you need to look no further than Download.com to find tons of free and usable players/recorders.
Also, some basic understanding of sound formats would come in handy. Basically you should ALWAYS first record to .wav, and NEVER to anything less than 44.1KHz 16bit (CD quality). Preferably, if your soundcard supports it, you should go for 96KHz 24/32bit, especially if you intend to edit or adjust the sound later on. With recording cassettes you might want to tweak eq and reduce tape hiss afterwards, and then all headroom in sampling frequency and bit depth is very useful.
Whatever format you want to transfer to later matters less, as long as you keep your original wavs pristine. Empty CDs being as cheap as they are it might be good practice to regularly backup your originals; there?s few things as annoying as having to re-record something you just threw out last week. And 44.1KHz 16bit wavs can be burnt straight to audio CDs with ANY burning program today. Then again, several burning programs can make ordinary audio CDs out of almost any kind of music file nowadays.
Hope this helped...
An oldie that does just what one expects and wants it to do. And luckily it still seems to be available at