to install Win 7 ? Not sure that you can do that .
You should be using the restore partition that's on the HDD.
Use the repair disc and image discs you created when new ...
If attempting a Win 10 installation, check with the maker to see if all of the drivers are available
There is a Toshiba Laptop (it's really old but I don't think that's the problem). The laptop is running very slow in normal mode and safe mode. I can't open some applications, disk cleanup included. The C disk is almost full. I don't think there is an anti-virus program on it but I can't install it now because it's too slow to download and install.
When I've tried to boot from USB to reinstall the operating system there is only a white line flashing on top left corner on the screen.
So what is the problem and how do I fix it?