Scrambled Noise At Higher Frequencies

Good day Win7 Community,

This is my first post on here, as many users, I come here because I am having an issue.

I bought my new computer at friday.
I began installing my desired programs and games.
But as I progressed I found out something was going on with my sound.

I own a 5.1 surround sound speaker set so I'd like to use it, I believe I have stereo sound on it right now because I want my speakers to have sound all the time instead of having either music or voice-only.

On to the issue;

At first, I used my audio outputs of my motherboard, but that didn't really work well with my speaker set.
So I got my old 5.1 surround card (PCI) out and installed it into my new computer and plugged my speaker set, I could now use all 5 speakers.

I uninstalled the motherboard sound drivers and installed the sound card ones.
Fiddled with the settings the way I like it (sound volumes on each speaker)

I got it all working.. only, with youtube,WMP,VLC Mediaplyer, whatever produces sound.
When a high frequentie sound comes along, it gets scrambled which really ruins my fun of my new computer.

List of hardware/Software:

Motherboard: ASUS P8H67
Sound Card: Trust SC-5100 5.1 Surround Sound Card

Motherboard Sound Drivers: Realtek High Definition Audio Driver

Sound Card Driver: Trust 5.1 Soundcard 14319

Recap:
I uninstalled Realtek and installed the trust 5.1 sound card drivers.
I tried fiddling with WMP's settings etc. but no luck so far.

I hope someone can assist me in this struggle.

EDIT: It is now occuring 90% of the time on the low-middle frequency.. it's getting on my nerves.

PS. I will be heading off to bed about 5 minutes after this message is posted, it's 4 AM and I've been trying to fix this problem of mine since this morning.

Regards,
BlackMaterial.

neo101 said:

I know its obvious but did you remember to disable the onboard (motherboard) sound chip in the bios?

What What What?

I might know a lot of computers and OS'.
But this isn't to my knowledge.

Please explain further, for the record, I haven't done anything else than described in the story above.

Thanks for replying.
Regards,

Thanks a lot for responding Mike Connor.

I've just updated all my system specs.
Wasn't all too hard, didn't have to use 'Speccy' though.

Status Update;
Defining scrambled,
Not the correct frequencies that sounds are transported on, they are either lower or higher, they fluctiate, which is quite annoying.

If any additional information is needed, it will be provided.

Regards,
BlackMaterial.

Is there some step-by-step guide?
I have never been in any BIOS.

I tried to acces my old computer's BIOS, but it asked me for a password, since I did not know it, I couldn't acces it.
Is there a chance there's a password on my current pc's BIOS?

If so, what might that password be?

PS, This audio card I am using, this is the card I have plugged in my 5.1 surround sound, so this requires me to disable the onboard audio? (just to get any doubts out of the way)

Regards,
Blackmaterial.