itunes sound problem

Hi, thanks for looking.

Just incase you need to know i have Windows 7, but this problem has only been going on for about a week and ive had Windows 7 for a few months so i dont think its relevant.

Well, heres my problem:

When i have itunes open and music playing the volume will drop. It does it at random, i mean it could do it 5 times within 10 minutes or it could happen once in 5 hours of listening to music.

In order to put the volume back up i have to click the speaker icon in the bottom right hand corner of the screen by the clock, then click 'mixer'. Then i have to move the volume level of itunes up to 100 again, it ALWAYS goes down to 13 when the volume drops.

Any help as to what the problem is and how i can sort it out would be greatly apreciated.

Thanks..

 

UPDATE: Now any video i watch in Windows Media Player randomly pauses. And if i pause the video myself, it will start playing again on its own for a while until, again, it randomly pauses.

 

I did all of the above and it seems to be fixed now. Thanks Halo