Well, first off, when did the problem start happening? What was he doing on the computer last? That's usually the best way to start solving a problem.
Dell Inspiron 9400 Notebook 120GB 5400RPM SATA HDD, 500GB 7200RPM SATA External HDD, DVD+-RW, DVD+-RW External, Mobile Intel Calistoga i945PM, Intel Core 2 Duo 2.0 GhZ, 2GB DDR2-667MhZ Dual Channel SDRAM, Nvidia GeForce GO 7900 GS 256MB Single-Pipe.
TinyXP Rev05, PerfectDisk, TuneUp Utilities, Window Washer, Nod32, Bo-Clean, SuperAntiSpyware Pro, Spyware Blaster, Comodo Firewall Pro.