How are you scheduling your script? If you're doing via the at command, then you must remember that it will be schedule to run under the system account. You can try scheduling runas /user:domain\user ..., but I never got that to work sucessfully.

The easiest way is to schedule it using the task scheduler (via start->Control Panel->scheduled tasks->right click->new->scheduled task (or the Vista equivalent)) where it allows you to specify the domain\user name and password. That works for me.

Or, see the command schtasks /?

Update: The following command worked for me. Note: You will be prompted for your password. I've wrapped the last option for posting:

schtasks /Create /tn fred /sc once /st 07:55:00 
/tr "c:\perl\bin\perl.exe \test\junko.pl
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use strict;
chdir "c:/Users/Admin";
my $fname = "output.txt";
#open OUTPUT, ">$fname" or die "$fname: $!\n"; is more common but you 
+will miss the message when run by scheduler
unless(open(OUTPUT,">$fname")) {
    exit
}
print OUTPUT "This worked\n";
close OUTPUT;
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Personally, I had nothing but problems when trying to schedule things with at.exe, or at least, too many. I got them to go away by using Schedule::Cron. The downside of Schedule::Cron is that it doesn't run tasks unless there is somebody logged in to the machine unless you make your "cron" into a service (with srvany.exe I guess).

If path is not the issue then permissions will be, either way if you were logging the error it would make debugging easier. As it happens scheduled tasks maintains a log file (Schedlgu.txt), in the c:\Windows folder. You can view the log from the Scheduled Tasks window by clicking View Log on the Advanced menu. You did look in there didn't you?

I suspect it fails to work because your script can not find "output.txt" (note you don't need to escape . in strings). The reason we don't know this is becuase you should be doing something like:

unless(open(OUTPUT,">$fname")) {
    log_error("Could not open $fname because $!\n");
    exit
}
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If you just exit silently you never know what happened. How you implement log_error is up to you. Writing to a file is generally easy and reliable although if you get a permission denied error on opening that how do you log that!

Could you give a simple example of using at with either /interactive and perl or wperl please?

Actually, I didn't need /interactive.

>type c:\script.pl
open(my $fh, '>>', 'c:\\script.out') or die;
print $fh (scalar(localtime()), "\n");

>at 1:59 perl c:\script.pl
Added a new job with job ID = 1

>at
Status ID   Day                     Time          Command Line
----------------------------------------------------------------------
+---------
        1   Today                   1:59 AM       perl c:\script.pl

>time
The current time is:  1:59:36.77
Enter the new time:

>at
There are no entries in the list.

>type c:\script.out
Sun Apr 13 01:59:00 2008
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