Ttyjfyk

I've installed Arch on a partition, and installed grup as the wiki says

grub-install /dev/sda
grub-mkconfig -o /boot/grub/grub.cfg

Now I only get Archlinux and Advanced options and no Windows.

Here's my parted -l output:

Model: ATA Hitachi HTS54757 (scsi)
Disk /dev/sda: 750GB
Sector size (logical/physical): 512B/4096B
Partition Table: gpt
Disk Flags: 

Number Start End Size File system Name Flags
 1 1049kB 135MB 134MB bios_grub
 2 135MB 269MB 134MB Mi msftres
 3 269MB 86.2GB 85.9GB ntfs Ba msftdata
 4 86.2GB 129GB 43.2GB ext4 misc
 6 129GB 236GB 107GB ntfs msftdata
 7 236GB 343GB 107GB ntfs msftdata
 5 343GB 394GB 50.8GB ext4
 8 394GB 403GB 9000MB linux-swap(v1)
 9 403GB 507GB 103GB ext4

And lsblk -f :

NAME FSTYPE LABEL UUID MOUNTPOINT
sda 
|-sda1 
|-sda2 
|-sda3 ntfs Windows 02F00D3CF00D3785 /media/Windows
|-sda4 ext4 25bc874b-1a89-4ff9-a01e-ca39e28155d9 
|-sda5 ext4 342ebed5-9592-4246-bdc2-4cd5c5ee92d5 /
|-sda6 ntfs Programming 01CE50F6C84EAFE0 /media/Programming
|-sda7 ntfs Entertainment 01CE50F6CC660CE0 /media/Entertainment
|-sda8 swap 374052bf-9a06-4c34-a1dc-616967b6fe4f [SWAP]
`-sda9 ext4 misc2 15b7261e-39a6-4668-9f22-a7c3096a6af5 /media/misc2
sr0 

My /boot/grub/grub.cfg content:

#
# DO NOT EDIT THIS FILE
#
# It is automatically generated by grub-mkconfig using templates
# from /etc/grub.d and settings from /etc/default/grub
#

### BEGIN /etc/grub.d/00_header ###
insmod part_gpt
insmod part_msdos
if [ -s $prefix/grubenv ]; then
 load_env
fi
if [ "$next_entry" ] ; then
 set default="$next_entry"
 set next_entry=
 save_env next_entry
 set boot_once=true
else
 set default="0"
fi

if [ x"$feature_menuentry_id" = xy ]; then
 menuentry_id_option="--id"
else
 menuentry_id_option=""
fi

export menuentry_id_option

if [ "$prev_saved_entry" ]; then
 set saved_entry="$prev_saved_entry"
 save_env saved_entry
 set prev_saved_entry=
 save_env prev_saved_entry
 set boot_once=true
fi

function savedefault 
 if [ -z "$boot_once" ]; then
 saved_entry="$chosen"
 save_env saved_entry
 fi


function load_video 
 if [ x$feature_all_video_module = xy ]; then
 insmod all_video
 else
 insmod efi_gop
 insmod efi_uga
 insmod ieee1275_fb
 insmod vbe
 insmod vga
 insmod video_bochs
 insmod video_cirrus
 fi


if [ x$feature_default_font_path = xy ] ; then
 font=unicode
else
insmod part_gpt
insmod ext2
set root='hd0,gpt5'
if [ x$feature_platform_search_hint = xy ]; then
 search --no-floppy --fs-uuid --set=root --hint-bios=hd0,gpt5 --hint-efi=hd0,gpt5 --hint-baremetal=ahci0,gpt5 342ebed5-9592-4246-bdc2-4cd5c5ee92d5
else
 search --no-floppy --fs-uuid --set=root 342ebed5-9592-4246-bdc2-4cd5c5ee92d5
fi
 font="/usr/share/grub/unicode.pf2"
fi

if loadfont $font ; then
 set gfxmode=auto
 load_video
 insmod gfxterm
 set locale_dir=$prefix/locale
 set lang=en_US
 insmod gettext
fi
terminal_input console
terminal_output gfxterm
if [ x$feature_timeout_style = xy ] ; then
 set timeout_style=menu
 set timeout=5
# Fallback normal timeout code in case the timeout_style feature is
# unavailable.
else
 set timeout=5
fi
### END /etc/grub.d/00_header ###

### BEGIN /etc/grub.d/10_linux ###
menuentry 'Arch Linux' --class arch --class gnu-linux --class gnu --class os $menuentry_id_option 'gnulinux-simple-342ebed5-9592-4246-bdc2-4cd5c5ee92d5' 
 load_video
 set gfxpayload=keep
 insmod gzio
 insmod part_gpt
 insmod ext2
 set root='hd0,gpt5'
 if [ x$feature_platform_search_hint = xy ]; then
 search --no-floppy --fs-uuid --set=root --hint-bios=hd0,gpt5 --hint-efi=hd0,gpt5 --hint-baremetal=ahci0,gpt5 342ebed5-9592-4246-bdc2-4cd5c5ee92d5
 else
 search --no-floppy --fs-uuid --set=root 342ebed5-9592-4246-bdc2-4cd5c5ee92d5
 fi
 echo 'Loading Linux linux ...'
 linux /boot/vmlinuz-linux root=UUID=342ebed5-9592-4246-bdc2-4cd5c5ee92d5 rw quiet
 echo 'Loading initial ramdisk ...'
 initrd /boot/intel-ucode.img /boot/initramfs-linux.img

submenu 'Advanced options for Arch Linux' $menuentry_id_option 'gnulinux-advanced-342ebed5-9592-4246-bdc2-4cd5c5ee92d5' 
 menuentry 'Arch Linux, with Linux linux' --class arch --class gnu-linux --class gnu --class os $menuentry_id_option 'gnulinux-linux-advanced-342ebed5-9592-4246-bdc2-4cd5c5ee92d5' 
 load_video
 set gfxpayload=keep
 insmod gzio
 insmod part_gpt
 insmod ext2
 set root='hd0,gpt5'
 if [ x$feature_platform_search_hint = xy ]; then
 search --no-floppy --fs-uuid --set=root --hint-bios=hd0,gpt5 --hint-efi=hd0,gpt5 --hint-baremetal=ahci0,gpt5 342ebed5-9592-4246-bdc2-4cd5c5ee92d5
 else
 search --no-floppy --fs-uuid --set=root 342ebed5-9592-4246-bdc2-4cd5c5ee92d5
 fi
 echo 'Loading Linux linux ...'
 linux /boot/vmlinuz-linux root=UUID=342ebed5-9592-4246-bdc2-4cd5c5ee92d5 rw quiet
 echo 'Loading initial ramdisk ...'
 initrd /boot/intel-ucode.img /boot/initramfs-linux.img
 
 menuentry 'Arch Linux, with Linux linux (fallback initramfs)' --class arch --class gnu-linux --class gnu --class os $menuentry_id_option 'gnulinux-linux-fallback-342ebed5-9592-4246-bdc2-4cd5c5ee92d5' 
 load_video
 set gfxpayload=keep
 insmod gzio
 insmod part_gpt
 insmod ext2
 set root='hd0,gpt5'
 if [ x$feature_platform_search_hint = xy ]; then
 search --no-floppy --fs-uuid --set=root --hint-bios=hd0,gpt5 --hint-efi=hd0,gpt5 --hint-baremetal=ahci0,gpt5 342ebed5-9592-4246-bdc2-4cd5c5ee92d5
 else
 search --no-floppy --fs-uuid --set=root 342ebed5-9592-4246-bdc2-4cd5c5ee92d5
 fi
 echo 'Loading Linux linux ...'
 linux /boot/vmlinuz-linux root=UUID=342ebed5-9592-4246-bdc2-4cd5c5ee92d5 rw quiet
 echo 'Loading initial ramdisk ...'
 initrd /boot/intel-ucode.img /boot/initramfs-linux-fallback.img
 


### END /etc/grub.d/10_linux ###

### BEGIN /etc/grub.d/20_linux_xen ###
### END /etc/grub.d/20_linux_xen ###

### BEGIN /etc/grub.d/30_os-prober ###
### END /etc/grub.d/30_os-prober ###

### BEGIN /etc/grub.d/40_custom ###
# This file provides an easy way to add custom menu entries. Simply type the
# menu entries you want to add after this comment. Be careful not to change
# the 'exec tail' line above.
### END /etc/grub.d/40_custom ###

### BEGIN /etc/grub.d/41_custom ###
if [ -f $config_directory/custom.cfg ]; then
 source $config_directory/custom.cfg
elif [ -z "$config_directory" -a -f $prefix/custom.cfg ]; then
 source $prefix/custom.cfg;
fi
### END /etc/grub.d/41_custom ###

Content of /etc/default/grub:

GRUB_DEFAULT=0
GRUB_TIMEOUT=5
GRUB_DISTRIBUTOR="Arch"
GRUB_CMDLINE_LINUX_DEFAULT="quiet"
GRUB_CMDLINE_LINUX=""

# Preload both GPT and MBR modules so that they are not missed
GRUB_PRELOAD_MODULES="part_gpt part_msdos"

# Uncomment to enable Hidden Menu, and optionally hide the timeout count
#GRUB_HIDDEN_TIMEOUT=5
#GRUB_HIDDEN_TIMEOUT_QUIET=true

# Uncomment to use basic console
GRUB_TERMINAL_INPUT=console

# Uncomment to disable graphical terminal
#GRUB_TERMINAL_OUTPUT=console

# The resolution used on graphical terminal
# note that you can use only modes which your graphic card supports via VBE
# you can see them in real GRUB with the command `vbeinfo'
GRUB_GFXMODE=auto

# Uncomment to allow the kernel use the same resolution used by grub
GRUB_GFXPAYLOAD_LINUX=keep

# Uncomment if you want GRUB to pass to the Linux kernel the old parameter 
# format "root=/dev/xxx" instead of "root=/dev/disk/by-uuid/xxx" 
#GRUB_DISABLE_LINUX_UUID=true

# Uncomment to disable generation of recovery mode menu entries
GRUB_DISABLE_RECOVERY=true

# Uncomment and set to the desired menu colors. Used by normal and wallpaper 
# modes only. Entries specified as foreground/background.
#GRUB_COLOR_NORMAL="light-blue/black"
#GRUB_COLOR_HIGHLIGHT="light-cyan/blue"

# Uncomment one of them for the gfx desired, a image background or a gfxtheme
#GRUB_BACKGROUND="/path/to/wallpaper"
#GRUB_THEME="/path/to/gfxtheme"

# Uncomment to get a beep at GRUB start
#GRUB_INIT_TUNE="480 440 1"

#GRUB_SAVEDEFAULT="true"

Thankfully I have experienced this myself and its not a serious issue.
Within the grub configuration, there will be a section for the different menu options. By default the windows option will have a # infront of each line (think its 4 or 5 lines in total). I'd like to provide you with more detail however I am not able to do so on my current setup.