Gremlins Emerge with Switch to Windows 7

since this is a laptop its likely that you are only willing to go so far, i.e. you have to strike a compromise between a dedicated server and a multitasking machine. The biggest degradation to audio transparency is (a) the audio hardware limitations (b) the jitter introduced by cycle stealing between computer processes... your audio card may have practically no jitter in a test lab situation but in a real life PC that doesn't happen without tweaking.

1) run your laptop off outlet power

2) setup a custom power configuration with all hibernate/sleep/idle options disabled... anytime the machine has to rouse hardware(video/CPU/HD/USB) from a power saving state it introduces audio degradation

3) if your BIOS has power saving options, note the defaults and disable (video/C1E) when playing music. Restore when on battery or your battery life will suffer

4) analog laptop sound card output is usually not great. Use ASIO if your only choice is analog out. Otherewise try to use digital to an external DAC. Kernel streaming is actually better than ASIO but can be more challenging to get working without stutters and dropouts

5) get DPC latency checker from Syscon. try to get your latency below 300 microseconds

6) once you have your latency cleaned up disable all audio buffering in your playback program or put to the minimums possible. I find that when I increase the buffers beyond the minimum for the output mode, the stereo image collapses.

PC's come out of the box as a jack of all trades (or master of none). To get them to perform as a music server you basically are doing what any good stock car racer has to do... strip out the useless parts for a performance vehicle from the standard factory model and replace highway performance parts with speed oriented parts.
Needless to say most don't want "race car" compromises in a comfortable suburban ride.