Hello,
Thank you for posting in the HP support forum.
Did you computer come with Windows 7 or Vista preinstalled by HP ?
As per the HP site, your computer does not officially support Windows 8/8.1 - only Vista and 7:
Windows 8 series hasn't been officially tested for this computer and it will work best with Win 7 or Vista.
The blue flashing is the so called "BSOD" - Blue Screen Of Death. There is something wrong - either hardware issue os software issue. Because of what you describe, I think this is software issue - some driver not working properly.
So, in my opinion, your options are:
>> Return to Windows 8.0 and keep using it
>> Reinstall Windows and install Windows 7 as it is supported officially
>> Try to run Windows Update to see if it will offer any drivers to install in hope that it may install new drivers and fix the issue
>> Try to install Windows 10 to see if it will work for you. Windows 10 comes with many drivers built it and may potentially work even though not officially supported by HP. You can create a free registration at Microsoft MSDN for evaluation and test Windows 10 Enterprise for free for 90 days (or less) to see if Windows 10 will work for you >> https://www.microsoft.com/en-us/evalcenter/evaluate-windows-10-enterprise . Eventually, you can purchase Windows 10 licence for Home or Pro editions
Looking forward to your reply. Please, keep me posted.