Installer trying to install onto non-existent drive

A friend called me about a problem he's had installing iTunes on his laptop (hxxp://www.apple.com/itunes/download/). The laptop is XP Media Centre. He tried to install iTunes whilst logged on with Admin rights and he got an error message saying that there was no J: drive so he was unable to complete the installation. He's not partitioned the hard drive or done anything "clever" (by his own admission he's an IT novice!). I had him check in Disk Management and it only shows his C: drive.

I downloaded the same executable to my XP Pro SP3 and started the installation process. It didn't whinge about the J: drive (no, I don't have a J: drive) so it can't be a problem with the executable.

I did some research and came up with the suggestion of creating a virtual drive (subst j: c:\<MyNewFolder>) but I've never tried this and do not know if it's likely to work or if it might screw up his system. Does anyone have any ideas?

I'd add that he lives a couple of hours drive from me so I don't want to give him some instructions that might get him into bother, requiring me to have to visit him to try to resolve any problem that I might have caused.

Thanks for your time.

UPDATE:

I don't know if this is relevant. I right-clicked the installation file and extracted the files. They are:

AppleMobileDeviceSupport.msi
AppleSoftwareUpdate.msi
Bonjour.msi
iTunes.msi
MobileMe.msi
QuickTime.msi
SetupAdmin.exe

I suspect that the final one is that which starts the whole installation process. I'm not familar with .msi files, other than knowing that they're used in a domain to deploy applications via Group Policy. Is there some way of easily examining the files to determine why the process seeks J:?

I'm happy to go with the virtual drive technique that I mentioned in my first post if that will be easier and won't mess up my pal's system.

I would have him go into add/remove programs, remove anything that has to do with iTunes, and try the installation again.

I just installed iTunes recently, and didn't see anything about a J:\ drive. Sounds like something went wrong in the install process.

I did some looking around on other forums, and found someone else with the same trouble.

The suggestion was given to remove iTunes Completely, and they gave this link for some guidance:

http://support.apple.com/kb/HT1926?viewlocale=en_US

tell your friend to give it a shot, hopefully it will help out.

Thanks westin, that's useful. I think he'll be able to uninstall anything related to iTunes, but it might be easier in the long term if I get access to his laptop using logmein (or similar).