Computer stability 
   RedAmber 

See also: Computer security

I recently had some PC problems and at first suspected a recent software install, I spent some time uninstalling, reinstalling, running Windows Restore and making BIOS adjustments before beginning to realise I might have a hardware problem.

Windows already has some diagnostic facilities, depending on version, but for example on XP try Start|Run and then any of...

Dxdiag can check various video and sound functions but really is checking the DirectX interface is OK.

Winver will display the Windows version and service pack level. With current editions of Windows you probably don't need to concern yourself with this as long as you either allow automatic updates or perform Windows Update.

taskmgr and perfmon (NT/2000/XP) will display information on running processes. If you have a performance problem you can first check which process is using most of the CPU, maybe it doesn't need to run! If you are running 95/98/Me you might try looking at Iarsn TaskInfo, I've found it useful in the past.

Perfmon is fairly technical but reveals much about machine performance with proper use. On NT you might consider running "diskperf -y" from the command prompt to enable disk performance counters, see 253251 on Microsoft's support site for more information.

None of the above will be any use if you have memory problems. When your PC boots it might indicate it is performing a memory check, this might show severe memory problems but it doesn't perform a thourough check and in effect is doing little more than giving you a false sense of confidence!

What is needed is an Operating System independent method of checking memory. Fortunately one exists, it is very good and free to download and use! It can be found at Memtest86 This is an excellent piece of software and I would recommend you try it. More detail is available from the web site just mentioned. Once you have downloaded Memtest86 you will need to have a floppy available, the downloaded software creates a bootable floppy that will run the memory tests when a PC boots from it.

Seagate offer tools for checking disks, also free to download. They are primarily designed to check Seagate hardware but they do perform general IDE interface checks also, see Seagate Tools

My PC is fine now, I discovered that one of my motherboard memory slots had failed, I removed memory from the bad slot and all was well (despite of course having less memory, but enough!). If Memtest86 does show problems on your PC you may need to do the same.