Connect tower to TV

Screen pc to TV

First, connect the powered-on TV to the PC's graphics card (s/VHS composite VGA plus audio) or HDMI
classic method "Vista" "Seven"
control panel; appearance and personalization; personalization; display settings click on screen 2; check extend the desktop to this screen; set the resolution to the smaller aspect ratio of the two screens; apply
second method (XP)
Go to control panel; double click on the control panel of your graphics card (Nvidia or GeForce)
configure multiple displays
select: clone and if the TV is not detected, turn it on and restart the computer
click on the link "my display is not listed"
Advanced display detection and if no TV is detected, click yes on the message and restart the PC
retrieve the audio signal: connect the audio cable to the headphone or SPDIF output (depending on) of your sound card right-click on the volume icon in the Windows notification bar
and choose playback device select the connected output and click on default
and restart the software to apply the changes
To switch to fully digital (see HDI HDMI)
connect the TV to the PC in the window select the type of display: mirror, extended, or only on external screen check: enable presentation settings
Pal, Secam 420p or 1080i?
see step 1 and go to your sound card in the section: change the HD signal or format of the driver select the type of connector you are using then click on the signal format that suits (ex: THD1080x2) click on apply to see the result and save the settings
for sound choose SPDIF by default

also explained by CCM:
https://www.commentcamarche.net/faq/24-diffuser-la-video-de-l-ordinateur-sur-un-ecran-de-television