Two ways for CDs to be played on PCs one is where there's a direct cable from the CD output to take audio of CD player to audio input of PC, other way is where the audio is read off digitally (via the 44 line parallel cable) and then processed back to audio in the PC.
Many of the older PCs had a "play" button on the CD drive, a volume control and sometimes a 3.5mm earphone socket.
Most newer PCs seem to have slimline CD/DVD players without these options.
You may have a number of different ways to play audio, using Windows Media Player, or RealPlayer, or some other audio software (eg WinAmp, a freebie).
Might be worth trying each of them - some may try to 'rip' (copy) the audio onto your PC. WinAmp had a built in graphic equaliser so you might boost the bass a bit.
(Just went off to find MusicMatch Juke Box but Yahoo! bought it, and then switched website to be some music store... MMJB was an audio player that could be used to play music in random order from selected genres and popular around 10 years ago.)
Which sockets on the PC and the amp are you connecting? If your PC has a line-out socket, connect that to the line-in or aux inputs on the amp. On the PC turn all the volume levels (the one on whichever media player you're using, plus the "wave" volume level and the master volume level) up to maximum.
If your PC doesn't have a line-out then I'm guessing you're using the PC's headphone socket. In that case turn the media player and wave volume levels up to max and start the master volume level about half-way and edge it up until it sounds best. Note that some media player's volume controls (eg, Windows Media Player) just change the master volume anyway.