OT: Why does XP choke on the filename - "com1.gif"

[Martin Baxter]

Please excuse the more or less OT question but I thought maybe one of the
wise people here might know the reason for this.

Yesterday I decided to transfer some old files from mac to PC via USB flash
disk.
Turned out there was a file in there called "com1.gif" (someone else sent
this to me a long time ago)
Windows XP refused to copy this to the PC hard disk.
It also refused to rename or delete it. Displaying an alert saying "Access
denied".

The files weren't important so I just gave up.
Then I tried to dial up using the modem on COM1. It failed to connect
because COM1 was already in use.

I cleared COM1 simply by restarting.
But I'm puzzled why this should occur. Despite the filename, I don't see
why trying to write an image file with this name should apparently result
in COM1 being opened. It makes me wonder if there are any other filenames I
should avoid.

Of course the cause might be something peculiar to my machine, but I
wouldn't know what.

Martin Baxter