Sometimes after I open Steam, it crashes, leading to a blue screen of death that says "page fault in nonpaged area." Strangely enough, it only happens randomly when I click on Steam. Sometimes it would go days without crashing. This BSOD only happens only when I start Steam at random intervals, I don't understand it. Game play is fine, no crashes or poor performance once Steam starts up correctly. Other than this, my computer never crashes or has problems of any kind; it is also 100% virus free.
I tried reinstalling Steam, updating my vid card drivers, repairing the Windows XP installation, and updating Windows itself to no avail. My bios does not have caching or shadowing options, so that is not a problem. Can it be faulty hardware or something? It just seems so strange that this problem ONLY pops up when I click on Steam randomly.
Some info about my PC incase you need it: I have a Radeon X1950 Pro graphics card,
Backup your files,
check your drivers are correct and up-to-date,
run memtest86+ to check your RAM isn't faulty,
find diagnostic software to check your HDD isn't faulty,
start replacing components with known-good components if it comes to the worst.