Aron said the noise was there even with the input disconnected or turned right down at source.
Looks like you're using a generic type of AC97 soundchip, probably one built in the pc motherboard, these are notoriously noisy on record, but those levels are particularly bad. The stereo mini-jack inputs are analog.
Check the Windows record mixer/selector. It could be that you are recording from other than the line input, maybe a "Stereo Mix", in which case you are getting everything coming out of the soundchip mixed back in with the input too.
You may have a poor quality cable too as Ocnor says, some of these mini jack adpters aren't very good. Keep the cable well away from any AC or transformers, but if the noise is there with it unplugged, it isn't the cable at fault.
The VM mixers were pretty good, so I would suggest getting something better in the pc, maybe with an s/pdif input which I think the VM does have? If you have the VM with the multitrack digital I/O, you can get an M-audio card that interfaces to it.
E-mu have a new range of PCI cards that a lot of people are praising. They now have a simple, cheap one with analog, digital and midi i/o - the 0404.
Then again, your computer could be a laptop - some makes produce terrible noise in the audio when running on AC power - try it just from battery. The noise is much worse when a cable connects the laptops ground to another items ground.