Hello Amber,
Thank you for posting your query in Microsoft Community.
I can understand that you have issues with random glitches in the Windows 7 computer. We will certainly help you with the same.
You may follow the steps mentioned in the link below to boot to low resolution mode and check if the issue persist.
Advanced startup options (including safe mode)
If that doesn't help, you may try to update the latest graphic card drivers and see if that helps.
HP 2000-227CL Notebook PC Drivers
Hope this helps. Otherwise, feel free to write us back for further assistance and we will be glad to help you ahead.