If my computer froze once or twice a week I would be pretty irritated by it. I was able to live with the fact that my computer took forever and a day to boot up (I later determined it was my CD Drive that was causing this, now I just only connect it when I need it) but there was nothing that actually had any problems once the computer was in windows. The video card was really loud too, but that was just because of how beastly it was (HD 4870), but that also didn't affect operations.
If I had something that actually caused my computer to lock up, though, I would be angry about it and sit there till it didn't do it anymore.
I am surprised you could tolerate locking up a couple times a week for a year.
That being said, I will try to help you fix all these problems.
The "BOOTMGR is missing" error can only be fixed by reinstalling windows, so it was a good idea to try to do that.
Unfortunately, your problem sounds like it is a Byzantine Error, which means that the thing that is problematic works like it is supposed to a lot of the time and doesn't work like it is supposed to some of the time. These sorts of problems tend to be harder to diagnose than other sorts of problems. If the problematic device decides to work properly during the test it can appear good when it isn't.
Kinda like how the Chinese built the Great Wall of China to keep the Mongolian hordes out of China and it did like it was supposed to until the Mongolian warlord paid off the gate guard and the gate guard opened the gates and the whole wall was rendered useless allowing the Mongols to conquer most of China. Inspection of the wall later showed it was in perfect working condition, it was just the one gate guard that caused the whole wall to fail.
Computer parts can work exactly like this.
The first thing I am going to suggest that you do is to try to download the program MemTest86 and create a CD Image out of the ISO. Special software is needed to deconstruct the ISO and make a bootable CD image out of it, you can't just copy the file to the CD. There are many programs that do this and one may already be on your computer if you have Roxio Easy CD Creator or something like that. Others are available on the internet if you just look up "Copy ISO to CD" or something like that.
After you make this CD, I would like you to insert the CD, then shut the computer down and disconnect all of the hard drives, then start the computer with only the following things connected:
Power Supply connected twice to motherboard and once or twice to the video card, if necessary.
Processor, RAM, Video Card, and CD Drive connected to the motherboard. Plug in the keyboard and the monitor as well.
Also, push down firmly on the RAM. If you think you will snap it in half that is too hard, but it needs to be all the way in there and it isn't always apparent when it is indeed all the way in there. If it isn't all the way in, that can cause all sorts of hard to diagnose problems. Push hard on it until you are convinced it is all the way in. The force needs to be perpendicular to the board (straight down) pushing at an angle can damage things.
Then start the computer again and boot off the CD. It will ask you which of 2 options you want to do. Either hit 1 or don't do anything and it will assume you want #1 anyway.
Then you will need to leave the computer doing this for a minimum of 8 hours. Longer if you can spare the time.
The only number you really need to care about is in the bottom right, number of errors. Keep an eye on that figure and see if it goes above 0.
Once you have left it in for a minimum of 8 hours, report back on the status. Feel free to repeat this test while you are sleeping at night for a few days in a row, it can't hurt. As mentioned before, like many parts, RAM can be subject to Byzantine Errors and the more test time you have on it the more confident you can be that it won't work most of the time and fail once in a while.
Facebook
Twitter
Instagram