Shut down box upon startup

Hi
My friend has a Mac Pro, hes not very good with computers so I told him I would try to help, his problem is that when he starts his mac the shut down box appears, the one with restart etc.
It can be cancelled but then a few minutes later it will pop back on again, I think he went through an update and during download he lost connection.
Is there a way to disable this, its driving him mental.

Tell him, to pop in the Leopard DVD and reboot holding down ;C: and if the machine loads, run Repair Disk from there. If no joy he may be up for a reformat of the drive and a clean install.

Then update to OS X.5.6 using the combo updater directly from the Apple web site. Keep us posted.

Mac OS X 10.5.6 Combo Update

Will that wipe any data or will it just cure the error, his macine runs fine normally but it just pops up with this shut down box like what happens when you normally want to do it but it does it randomly.
It doesnt shut down for you though, just give you the standard options.

He shouldn't do a reformat and install until he is totally sure that he has to.. Just do a install over the current and if that doesn't work and archive and install, still no go a clean install might be what he has to do. If a clean install is done, then he will loose all of his data so he might want to back up the data that he wishes to keep.

Seems to have fixed itself