sudden unpredictable audio noise

[bobj]

I am trying to transfer video (and audio) from VCR tapes to DVD.

During capture at totally unpredictable times, a staticy noise will start; it could be after a minute or an hour. As soon as I "Stop Capture" it will stop.
I suspected and think I have ruled out: electrical interference from a motor on the same circuit starting up; the VCR or tapes since it will not happen when playing on tv; some sort of interference from the internet by disconecting from the internet; my capture software because it happens with three different programs.
I also minimize the window so the video does not even show in case it may be coming from that. Obviosly, I don't know what I doing but just trying to hit upon something.

I use a Plextor digital video converter; XP Media Center Edition Version 2002 SP 2 on a HP Pavillon; 1G memory, 512 cache; 1.61 GHZ.

I have checked connections multiple times. It will just start "buzzing" with nothing else going on.
I figure it must be internal to my computer since it will stop as soon as I stop capturing and do not need to do anything to the vcr or Plextor to resume capturing without the noise and it does it regardless of software used

I'm stumped. Help please

[Soopafresh]

So many things could be the culprit, from the motherboard to the capture program. You'll probably have to try one thing at a time and figure it out via deduction.

[SingSing]

Ground loop.

Take a wire and touch the conductives part of both equipments, and you should be able to determine changes .

It can be solved by plugging both equipment into the same power strip with three pronge plugs.

Unless the internal ground connections of one of the equipment is loose. Change one of the equipment to determine which one.

[bobj]

Thanx for trying to help.

I have no idea how to check out the motherboard; I was hoping this was a common problem with just a few possibilities.

Sindgsing, I'm not sure I follow what you are saying. Both the computer are plugged into the same power strip. The convertor is powered through the USB port. I will try to plug them into different house circuits.