silly trivial computer question

[ua1176]

what would cause my computer to occasionally revert to the default "windows xp" display theme? i set it to "windows classic" (just looks nicer IMO) but every so often when i turn it on/restart it, it reverts to the "windows xp" theme.

is this indicative of anything that i should be concerned about? i know its silly but i depend on this computer to hold up for 10 hours a day every day, and im also just curious about why this would happen.

(if it makes a difference....the computer in question is totally clean. no internet, no cracks, no porn. just Pro Tools, a few plugins, and a CD-burning program)

thanks,

jon