Blue Sreen Twice A Month

[LJScott]

I am using a home school computer desktop. It is HP but older model not sure what type. It has 4 USB ports in front, to circle jacks for a mic and one for headphones, power button right below the USB ports, then the disc drive below that. Twice a month around the same time it blue screen, First it stalls quickly, then the monitor shows these horizontal lines, then it goes out for a split second and then blue screens. When it comes back on it takes way longer to boot up then it usually does after this. And each time this happens, the browsers I try, no matter which ones they are, show up in task manager about 5 times when I only have it up once (especially Firefox). How can it possibly do this at nearly the same time of every month?:

 

[nagazai]

First, saying how it looks like helps nothing, since that's just the case model. open your startup menu, type dxdiag. Save the results in a txt file and copy the content here.
Second, take a picture with your cellphone of the bluescreen. The error appear there, and we can solve from that.
Try seeing what YOU are doing every time when that happen. If it happens every month exacly 1 month later, could be an update, something related to your house, maybe someone using it incorrectly.
As for the task manager, if you are saying about process, thats normal. It will appear many open. if you are talking about actual programs repetead, try reinstalling them. Should be this simple to fix.