Screen with wavy lines

First try changing the screen resolution and check if it works.
Step 1.Right click on the Desktop and select Display Settings
Step 2.Select Advanced Display Settings
Step 3.If you have more than 1 screen connected - select the screen you want to change
Step 4.Click on the Resolution drop down box
Step 5.Select your desired resolution
Step 6.Click Apply.
If the above step fails then you will need to update the display adapter drivers on the computer and check.
How to update the graphics card driver on the machine
Step 1.Right click Start/window
Step 2.From the list of results click Device Manager
Step 3.Under Display Adapters, double-click the entry for your Display Adapters, and then click the Driver tab.
Step 4.Click Update Driver Software.
Step 5.Follow the Update Driver Software Wizard to update the Display Adapters driver.

Update a driver for hardware that isn't working properly