|"I reinstalled my OS"|
Whenever you load Windows from a regular Windows CD (or DVD) from scratch, after Setup is finished you must load the drivers for the mboard, particularly the main chipset drivers, in order for Windows to have the proper drivers for and information about your mboard hardware, including it's AGP or PCI-E, ACPI, USB 2.0 if it has it, and hard drive controller support. If you have a generic system and have the CD that came with the mboard, all the necessary drivers are on it. If you load drivers from the web, brand name system builders and mboard makers often DO NOT have the main chipset drivers listed in the downloads for your model - in that case you must go to the maker of the main chipset's web site, get the drivers, and load them.
Load the main chipset drivers first.
The integrated video drivers are probably not built into XP - in that case, you must install them.
You can connect from the S-Video port on the computer to the S-Video port on the TV via a legacy S-video cable (4 pins) , or from the S-Video port on the computer via a SVideo (4 pins) to RCA adapter at the S-video port to an RCA cable to a YELLOW RCA composite video jack video input on the TV,. or from the S-Video port on the computer via a S-video to RCA cable to the YELLOW RCA composite video jack video input on the TV, but you can NOT connect to both the S-Video jack on the TV and the YELLOW RCA jack on the TV at the same time - you connect to one or the other.
You may need to select a different video input on the TV for the S-Video and RCA YELLOW jack. There may be more than one YELLOW RCA jack.
Windows often defaults to enabling only ONE video output. Go to Display Properties - Settings and hold your cursor over the two displays - if one shows Not Active, you must RIGHT click on it when the cable to the YELLOW RCA jack or the S-Video port on the TV has been plugged in properly, and enable the display.
Windows will retain enabling the TV OUT display as long as the cable to the TV is plugged in while Windows is running, but when you unplug the cable at least once then boot Windows with it unplugged, Windows will often have only one display enabled after that, until you connect he cable and enable the TV OUT display again.