want hard disk to work on windows laptop as well as my macbook air

Windows cannot natively read or write to partitions or volumes formatted as either Mac OS Extended (Journaled) or APFS. You'll need third-party software in order to do this.

The startup volume/partition for a Mac must be formatted as either Mac OS Extended (Journaled) or APFS, so using a common filesystem such as ExFAT or FAT32 for your boot drive wouldn't be supported. However, you could create another partition on the drive that is formatted as either ExFAT or FAT32 (MS-DOS FAT). Windows and other operating systems can read and write to these two formats.

Although Windows can also read and write to NTFS-formatted volumes or partitions, macOS only has read support for NTFS and cannot natively write to NTFS-formatted volumes.

depending on what you are doing with it it could be expected behaviour.

If you are trying to share and manage files you are best if possible to set it as network storage (connect to router or share over the network connected to 1 computer all the time)

if you are using it for an time machine back up you will need to partition it for the TM, and then for additional storage.

Any other options will require reformatting and or, adding software to the computer to read/ write the other computers file type