If Latency is the symptom, there is nothing wrong with your MIDI Cable. 
    This delay is to be expected when a Sound Card does NOT have a Hardware
    Synthesizer on board to process the flow of MIDI data. Most current 
    desktops and all notebooks, do not have a hardware Synthesizer. 

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The "MS GS Wavetable SW Synth" is a software based synth that will not allow 
you to use the 'MIDI In' signal flow adequately. Typically, this synthesizer
for the WDM Model has a lag (delay) of about 250 milliseconds (a quarter of 
a second) from the time you start playing a note until the time you hear it. 
This makes it not very useful for this type of application.

You would need to use your Sound Card's proprietary MIDI Driver instead of
a 'generic' 'universal' driver. If it is not available because it is not 
installed, please consult with your Sound System's documentation to find 
out which Driver should be used for MIDI.

If the only driver that works with your soundcard/soundchip is the "MS GS 
Wavetable SW Synth" or "Microsoft MIDI Mapper" then that's really not good
for MIDI. MIDI is becoming obsolete anyway. Turtle Beach (the leader in 
on-board Synths since the MultiSound days - 1990) does not develop Sound 
Cards with on-board Synths any longer. The last board with this feature was 
the Santa Cruz, which is discontinued.  

If MIDI is important to you, you should be looking at other options available
nowadays such as external synth modules. They offer superior sound quality 
and prices have come down substantially in the recent years.
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