Once, my friend from job asked me to "check out" his 6-years old pc. It worked like **** -litterally, I need to wait for any reaction. Even mouse movement was delayed. So i thought, that simplest solution will be full installation.
But that was mistake -_- At first I've tried instalation form cd. It started very well, half hour passed. But pc wasn't able to finish the whole installation. And after that I couldn't start another one. I've downloaded different versions of windows,on my bootable usb. It took another amount of time. For test I've installed them on my laptop. But on his ****** pc it wasn't working. There was something seriously ****** up with mother board, or just port's cd. But I had no way to check it. There was no way to revive this zombie. SO, I had give up. He was pissed on me. I was pissed, because I've lost 5 hours from sunday. remember. Never do free jobs for friends.

Professional or not. After you've tried turning it off then on the next step should most definitely be a backup.

It's hard to do anything, when waiting for response takes >10minutes. At first i just used repairing tools from windows cd. Then I asked, if I can mae ull reinstallation. And I said it will takes only a while, and he will have new, clean system ;-(

I guess... I'm not professionalist. I tried my best. If remember after failed instalation i was looking for bootable software too. And I downloaded something. But It couldn't start anymore. Usb just stopped working. I couldn't boot anything.

It was a bad hard drive.

I guess this one was. But I have 5,5 years old laptop(asus k51in) and it works pretty well, Sometimes i'm even taking it on trips. I didn't expected from it survive that long, without maintenance. Olny once I've dropped it from stairs. And sometimes it may shows green dots on screen.

I have a 7 year old HDD in my beast machine that still runs fine. Takes awhile to boot up, but works just fine, otherwise.

However, if you're already having problems with it, and it won't take a recovery/clean install, it's a bad hard drive. If you really want to make sure, just run a smart test.

Could also be the mobo, but that's specifically with prebuilt newer computers with newer OS's.. They virtually tattoo Windows Authentication keys into the motherboard and sometimes will refuse to take a new OS if it doesn't have a proper key.

There's nothing wrong with HDDs. Just lack of protection and careless users.That kills pc. That's why I suggest some people macs. They are expensive. But suitable for dumb and old people.

Programmer? What language? C++/JAVA?