Assuming it's not the Windows blue screen of death, some things to check:
-If using Windows 10 or 11, check that Windows has been given permission to use your camera and microphone: Windows Settings>Privacy & Security>Camera>turn on camera access and lower down the page, turn on “Let desktop apps access your camera”.
Do the same for the microphone (click on Privacy and Security in the left margin to return to the main screen to access the Microphone).
-Check you've got the correct video input selected: Composite or S-Video (missing in the v7 manual), this screen:
-If you don't see any video on the next screen (after clicking Continue), try another tape. If still no video, do a check of your VCR: plug it into your TV (analogue inputs) and see if you get a picture.