The recommended thing to do (if you forgot to make the recovery disks) is to order them with Asus.
But depending on what you mean with "the HD was formatted" (disks aren't formatted, only partitions are) it's possible - in principle - that a little bit of editing the partition table will allow you to boot from a recovery partition to install Windows 8.1 again. But probably you need an expert to try that.
Kees
Hi there
I have an acer laptop that came pre installed with 8.1 on it but no OS disk
The HDD was formated and now has vist on it
There is a sticker on the back with bar code numbers
Not sure if they are the win 8.1 product code or not
But if it is can I download win 8.1 for free onto that machine
Thanks
Batista23

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