It looks like people who want to get the Surface Pro tablet want as much hard drive space as possible. The Microsoft Store website in the US is now showing that the $999 128 GB version of the Windows 8 Pro tablet is now showing as “out of stock” just hours after it first went on sale.

The Staples.com website is also showing the 128 GB version as “currently out of stock.” The Surface Pro listings on Microsoftstore.com and Staples.com still shows the $899 64 GB version as being available. The Canadian Microsoft Store site still shows both versions on sale. The Best Buy website shows both versions of the Surface Pro as being available, but not for online shipments; there’s still the option of ordering the tablets online and then going to your local Best Buy store to pick them up, again if they have them available.

Microsoft has not commented on how many units of the Surface Pro tablet it made available for the initial shipment. Unlike the launch of the Surface RT product, Microsoft did not offer pre-orders of the Surface Pro ahead of today’s launch. That might indicate that the company kept units numbers down to ensure that they had enough to meet demand. Obviously, they didn’t anticipate the more expensive version of the tablet would be more popular.