X:\>dir 979536.exe
 Volume in drive X is RAMDISK
 Volume Serial Number is 065B-0000

 Directory of X:\

05.07.2012  22:04           121.535 979536.exe
               1 File(s)        121.535 bytes
               0 Dir(s)     129.867.776 bytes free

X:\>dir "979536.exe"
 Volume in drive X is RAMDISK
 Volume Serial Number is 065B-0000

 Directory of X:\

05.07.2012  22:04           121.535 979536.exe
               1 File(s)        121.535 bytes
               0 Dir(s)     129.867.776 bytes free

X:\>perl -Mautodie -e "open $f,'979536.exe'"

X:\>perl -Mautodie -e "open $f,chr(34).'979536.exe'.chr(34)"
Can't open($fh, '"979536.exe"'): Invalid argument at -e line 1

X:\>type openfail.c
#include <stdio.h>
#include <errno.h>

int main(int argc, char ** argv)
{
        FILE * f;

        if ((f=fopen("979536.exe","r"))==NULL) {
                perror("open without quotes");
        } else {
                fclose(f);
        }

        if ((f=fopen("\"979536.exe\"","r"))==NULL) {
                perror("open with quotes");
        } else {
                fclose(f);
        }

        return 0;
}
X:\>gcc -Wall -pedantic -o openfail.exe openfail.c

X:\>.\openfail.exe
open with quotes: Invalid argument

X:\>