The new versions of Windows are becoming more user friendly and hide from the user many settings. At the same time, these settings have a significant influence on the sound recording. Consider the most important nuances.
Windows 7 support two modes of sound card: Exclusive and Shared. Exclusive mode guarantee smaller latency(good), but only one program may use sound card at a time(bad).
Some audio players will attempt to enable exclusive mode that will block the record. To avoid this you need to open Sound Card Properties and turn off "Allow applications to take exclusive control of this device"
If your sound card work in shared mode then all applications should use same audio format for both playback and recording. If audio stream has different sampling rate then it should be resampled to default format. In general, this reduces sound quality. It will be good idea to use same audio format in recorder settings. Run audio recorder, open settings, select desired audio codec and set the default sampling rate.