После установки arch не появился windows в grub, os prober установил
sudo grub-mkconfig -o /boot/grub/grub.cfg
вводил не помогло
sudo fdisk -l
Disk /dev/sda: 931.5 GiB, 1000204886016 bytes, 1953525168 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 4096 bytes
I/O size (minimum/optimal): 4096 bytes / 4096 bytes
Disklabel type: dos
Disk identifier: 0x3b06f5a8
Device Boot Start End Sectors Size Id Type
/dev/sda1 * 2048 1026047 1024000 500M 7 HPFS/NTFS/exFAT
/dev/sda2 1026048 409602047 408576000 194.8G 7 HPFS/NTFS/exFAT
/dev/sda3 409602048 630171647 220569600 105.2G 5 Extended
/dev/sda4 630171648 1953521071 1323349424 631G 7 HPFS/NTFS/exFAT
/dev/sda5 409604096 417992703 8388608 4G 82 Linux swap / Solaris
/dev/sda6 417994752 630171647 212176896 101.2G 83 Linux
Partition table entries are not in disk order.