While I haven't had this specific problem, I've had my share of troubles with MC7. What worked best for me was to perform a clean fresh install off the Windows 7 DVD - not an upgrade. After updates and a few other installations, I set the virus scanner to ignore the RecordedTV Library. This made MC7 very responsive. I had also had other issues with setting up the HDHomeRun dual-QAM tuner that contributed to instability and a black screen for MC7. This cleared up with the HDHR beta driver set and the virus scanner exclusion mentioned.