rec. problem

[PCFour]

i was messing around with cool edit pro the other day and didnt have my mic hooked up...i recorded on a track an noticed that there is still some noise when the mic has no connection to the computer...i thought the wav was supposed to be flat...im buying a usb pre soon but i was just wondering what this is coming from...look at the pic...thankya

[PCFour]

had to add something else that gives me trouble...when ever i record, my voice only records mostly on the left side, so i have to go to control panel,sounds and audio devices,voice tab, and test hardware, and then it records equally, i had no problem doing it the first time but i have to do it every time i turn on my computer, any help? thankya