Now grab the correct Debugging Tools for your version of Windows. Run the downloaded package to install it.
The debugger will download data called symbols to help diagnose your crashes. Create a folder like c:\symbols where these can be stored.
Click Start > All Programs > Debugging Tools for Windows > WinDbg to launch the debugger (Windows Vista users must right-click the WinDbg link and select Run As Administrator).
Click File > Symbol File Path, type SRV*c:\symbols*http://msdl.microsoft.com/download/symbols (replacing c:\symbols with the folder created on your system) in the Symbol Path box and click OK.
You've now finished the set-up process. In future, any time you want to diagnose a crash, all you have to do is launch WinDbg, click File > Open Crash Dump, and point the debugger at the dump file created by your latest crash (this is a file with a .DMP extension, probably Memory.dmp, stored in the Windows or Windows\MiniDmp folder). The debugger will open the file and analyse it, which could take some time - be patient.
If you're in luck then it will identify the file for you with a line like 'Probably caused by : filename.sys'. This information isn't always correct, so treat it as an indicator only. If it points to a firewall you installed a month ago, say, then treat the report seriously, uninstall or upgrade it. But if it names a core Windows component, or an application you've never had any problem with before, then be more sceptical. Search at Google for more reports of crashes with that file before you take any serious action.
5. Other ideas
If even the debugger can't help then it's time to try more general measures.
Simplify your system by unplugging and removing all unnecessary hardware, for instance.
Browse the Start > All Programs menu and uninstall any applications you don't use any more.
Click Start (then Run if you're using Windows XP) and enter devmgmt.msc to launch Device Manager. If this detects a problem device then it will be highlighted with a yellow exclamation mark. These could be another symptom of the problem behind your Windows crashes, so double-click any highlighted devices for more clues.
Check that you're using the latest version of every program you've decided to keep (use UpdateStar at www.updatestar.com to instantly locate these updates for you).
If you're running short of hard drive space then use the Windows Disk Cleanup applet (Start > All Programs > Accessories > System Tools) to create a little room.
And if you have very little RAM - 1GB or less on a Windows Vista PC, say - then try adding more. It's ludicrously cheap, starting at £10 for a 1GB DIMM, and can make a huge difference to your system.
