Your computer shuts down when you are downloading multiple files at once. But not at any other time?

Answer 1

If by 'shut down' you mean 'suddenly and completely, totally loses power- fans, lights, everything.' Then it is a hardware problem, and a serious one at that.

If by 'shut down' you mean crashing, freezing, hanging, or shutting down as if you restarted to selected 'shut down' then it is a software problem. Reinstalling your OS will probably fix it. If you don't have one, I also suggest using a virus scanner as a virus could be the cause- but not usually.

If this is the first scenario, then it is a hardware failure. This sort of behavior typically occurs when some device that uses memory, or said memory, has failed. Why it may be occurring with multi-downloads only has to do with the way Windows handles buffering.

If you have only one or two smaller, or slower files being written, it is paged directly to the disk- IE, it writes to the harddrive as the file is downloaded, in real-time. If there is a lot of data moving quickly, or many files at once, it will use the Hard Drive's buffer- A small bit of RAM used just for 'storing' files until the harddrive can catch up. Usually this comes in 8MB, 16MB, and 32MB sizes. If this buffer is bad it can cause errors, but not typically power-loss. However an electrical flaw in the harddrive could trigger the Power Supply's safety shutdown procedure- Kill the power before something fries.

In the case of MANY files or very fast-loading files, actual RAM is used to store it until the Buffer can catch up and hold the rest. If your RAM is unstable, then crashes could occur at that time. Most commonly systems will appear stable under normal operation even when the RAM is bad, depending on what manner in which the RAM is bad. My memory, for example, is stable during everything, even gaming- however if I go into standby, hibernate, or data stays 'stored' for long periods of time, it will corrupt and cause crashes, bluescreens, errors, and even sudden power loss, or loss of video only. I fixed this by changing the DRAM timings so that it ran at 5-5-5-15-30 timings instead of 5-5-5-15-20 timings. Please note this IS an advanced step and you should ALWAYS contact the manufacturer BEFORE messing with timings. Improper timings can permanently damage your computer.

To test your RAM, try Memtest or running SiSoft SANDRA's tools. You'd be surprised how many people think their PC is fine but, in fact, has bad RAM that only causes problems 'once in a while'. That random crash to desktop in a game? May not be the game at all!

It may also be the power supply. If it's too weak and is being overloaded, the extra work of handling a full-throttle network transfer of multiple downloads may just push it over the edge- but this is unlikely. If your PSU is less than 2 years old and is 750 watt or more, you are probably fine. Otherwise, it can't hurt to test it- try reducing the power draw and see if the problems persist. Unplug things you aren't in immediate need of- Extra video cards, CD-ROM drives, anything USB, etc.

Finally, if it's the motherboard, it can also cause these problems. Failing motherboards can have all sorts of unusual symptoms and are very hard to pin down. Since it's the least replaceable component, the problems may persist even after you've tested every single other component. Bad motherboards rarely show up in benchmarks, memory tests, etc. And are only suspect once you've tested the CPU, RAM, and Hard Drive thoroughly (more than 8 hours -straight- nonstop testing at 100% load)

Bad motherboards are the third most common computer ailment, but the hardest to find and fix. Inexperienced technicians (which sadly, MANY are) will often replace devices that are known to cause such issues, but not actually fix the error. For example- a bad motherboard may show graphical errors and crashes in games. This makes you suspect the videocard, but may not in fact be the problem.

The most common components to fail in a PC:

1) Harddrive

2) Motherboard

3) Videocard

4) Power Supply

5) RAM

6) Other Peripherals (Soundcard, Network cards, modems, etc.)

7) CPU [Rarer for AMD than Intel, but even Intel CPUs almost never fail under normal conditions. This is due to Intels being clocked higher and producing more heat than AMD equivalents. A trade-off, you get more speed but lower life expectancy- only 4 years instead of 5. But who cares? In 4 years you'll probably have a new PC anyway.]

Hope this helps!