my sound card which is a C-Media sound card model Cmi8738/c3dx PCI is giving me some problems during recording

my internal driver that originally came with my motherboard seems to have a bit of a problem when recording (auto flanger effect) and
i bought a new one which is the C-Media sound card model Cmi8738/c3dx PCI and now when i record with the pc microphone, there is a sharp FEEDBACK disturbance. I've tried cool edit pro as WELL as the basic windows RECORDER to record, and the feedback sound is STILL there!

any tips on this one guys?
i really NEED this to finish up my projects

thanks !!!!!!!!!!!!!!! To eliminate microphone feedback, make sure sound is not feeding directly to the speakers. To do this, double-click on the speaker in the TASKBAR. Once the window opens, make sure the recording and microphone volume controls are there. If not, select Options, then Properties, and check the microphone and recording monitors.
Now close that window, and mute the recording and microphone volume controls.