It is required to check whether it is a Hardware issue or issue related with any Software. For this,
login to BIOS by continuously tapping the F2 key on the startup, if you can view vertical lines in the BIOS, it will be a Hardware issue related to the LCD monitor, and it is required to service the Computer in any service center.
If the vertical lines disappear in the BIOS mode, the issue is with any of the Softwares or drivers installed in the Computer.
Resolution steps:
1. Check whether the installed video driver is compatible with the Computer. you can download Original shipped Video driver
here.
2. You can also try updating the BIOS version by downloading and installing the
BIOS updater.
Please try the steps in the same order as it is provided. All the best.