ihave had problems with my dell xp5 400 shutting down at various times without warning. When it comes back on I get a fatal error message stating that the computer has recovered from a fatal error. The error signature is bccod:1000000a bcp1: 00005E4 bcp2: 0000002 bcp3:00000000 bcp4: 804E820E OSVer: 5_1_2600 SP:2.0 Product: 256_1

I have also random lost digital photograph files.

How to perform advanced clean-boot troubleshooting in Windows XP (http://support.microsoft.com/default.aspx?scid=kb;en-us;316434)
Also, check ram for errors.

recover *.chk files (http://www.ericphelps.com/uncheck/)
For the lost pictures

You might backup your pictures online with something like Google
Picassa.