Capacity of SanDisk SD7SN6S-512G-1006 lower than expected

I have an HP Laptop with the following SSD:
Model Name: SanDisk X300 Solid State Drive
Model Number: SanDisk SD7SN6S-512G-1006
SATA Revision: Gen3
SATA Link Speed: 6.0 Gb/s
Serial Number: 152695401359
Maximum LBA: 1000215215
IEEE OUI: 01b44h
4k Alignment: Yes
The firmware version is X3511006

Based on the model number, this appears to be a 512Gb drive. However, windows is showing it as 128Gb. I booted my machine with Linux, and it shows the same thing.

What am I missing here? Why with a model number of 512G would this only be a 128G drive?

Thanks

Open disk management by right clicking on “my computer”, or “this computer”, and then “manage”, or just search the start menu, then look at the drive. I bet the drive was partitioned to 128GB for the boot partition, perhaps cloned from a 128GB disc, you have to add additional partitions in disc management to access the rest. It may let you resize your boot drive, I can’t remember if so.

#SanDiskUserRewards

Thanks. That was the first thing I tried. It shows no additional unallocated (partitioned) space. I’ve submitted a support ticket.