is it possible to store the blockchain in two different hard drives that works simultaneousley?
Raid controllers or "software (fake) Raid" can achieve this, with a mode called JBOD (Just a Bunch of Disks), it will look to the OS like a single drive.
I would recommend Linux, but it might be possible to do it in windows if the motherboard has such mode. Although Raid 0 works, that needs two drives of identical size (or one of them would have wasted space). Raid 0 increases the chance of data loss if a problem occur with the drives, but the blockchain can easily be recovered anyway and it happens to be faster.
In Linux, you could use LVM as
mentioned above.
There are also specialized filesystems that support this as well without LVM: Btrfs, and ZFS to name a couple.
If your drives are so small that you need two to fit the entire blockchain, perhaps you should consider simply getting a larger one. A cheap ($18) 250g drive should fit the blockchain now, but give it some room for the future: you can get a
500g drive for $20...