I am so glad that I found this method. I bought a Bolt VOX with a 1TB drive. Everything that I found on this site told me that the only way to get 4TB of storage (which is what I want) was to drill a hole in the Bolt and connect an external drive to the internal SATA port on the Bolt. The above advice is NOT the only way to skin this cat. There is a way connect an external drive to the eSATA port without cutting any holes in the Bolt's case.... without paying hundreds of dollars to a 3rd party company (which shall remain nameless). Yes, that's right. You are not limited to using the (discontinued) Western Digital (WD) DVR Expander line of products. For the naysayers among us: Yes, I realize that two drives means twice the possibility of hardware failure, and that if the external drive fails... I will lose all of my recordings. I am willing to live with this risk until the end of my 24 month warrantee. Also: Advice for anyone who wants to do this: Choose a 3.5" external drive that uses PMR, not SMR. (If you don't know the difference between PMR and SMR, click here: LMGTFY) I am new to Tivo (I am a Windows Media Center user since 2011). I just converted to Tivo and I really don't want to drill holes in my brand new Bolt until after the warrantee is expired. So... are you ready to learn how to do this? First, go to the link below. Download either the ISO or the USB/HD file. MFS Tools 3.2 Next, burn the ISO to a CD/DVD... or use Balena Etcher (balenaEtcher - Home) to create a bootable flash drive (requires a 2GB or larger flash drive). You could also use Balena Etcher to write the image to an HDD, and use that as the boot device. Then, configure BIOS on a PC so that it will boot from the CD/DVD, flash drive, or HDD that you created in the step above. NOTE: I connected the drives to the SATA ports inside an old desktop PC that I had lying around. If you don't have access to an old PC with SATA ports, you can use USB-to-SATA adapters. WARNING: I wrote the below paragraph because my Bolt was brand new, so I had to go through the setup process on the Bolt before I could use MFS Tools to configure the external drive so that it can connect to the Bolt's eSATA port. If your Bolt already has recordings on the internal drive, following these instructions will delete all of the recorded shows on your Bolt's internal drive. After you finish the normal setup process on your Bolt, unplug the Bolt and remove the internal hard drive. See video at the link below for instructions on how to disassemble your Bolt: NOTE: The video says that you need a T10 Torx bit (he calls it a "security" bit). My Bolt VOX needed a T9 bit, so YMMV. Perhaps the older version used a T10? I don't know. Remove the internal HDD from the Bolt, and connect it to your PC. Connect the HDD that you plan to use as an external HDD to the PC. I used a Western Digital (WD) WD40EFRX. I purchased it from Amazon here: https://www.amazon.com/gp/product/B00EHBERSE/ref=ppx_yo_dt_b_asin_title_o03_s00?ie=UTF8&psc=1 Turn on the PC and boot into MFS Tools. It runs a Linux variant. Once the PC is booted and ready for you to login... enter the username "root" (without quotes) and the password is "tivo" (without quotes). Make sure that CAPS LOCK is turned off. Username and password are lower-case. Now, type the following command to identify the drives that are connected to your PC: Code: lsblk -o name,size,vendor ^^^ those are lower-case L's (ell), not I (eye) or 1 (one). My Bolt came with a 1TB drive, so the original Bolt drive was something like 997GB. It was "/dev/sdc". My new 4TB drive showed as something like 3.7TB. It was "/dev/sdb". Now, type the following command, where sdX is the original drive from the Bolt, and sdY is the drive that you will use as the external eSATA drive: Code: mfsadd -xfm 2040 /dev/sdX /dev/sdY It should finish in less than a second, with a "success" message. Now, install your new drive into an external enclosure that has an eSATA port. I used the Rosewill RX304-APU3-35B enclosure. I purchased it here: https://www.amazon.com/gp/product/B00N1Q2M6A/ref=ppx_yo_dt_b_asin_title_o03_s00?ie=UTF8&psc=1 The Rosewill RX304-APU3-35B comes with all necessary hardware, including an eSATA cable. NOTE: The developer of MFS Tools told me that external enclosures which encrypt the contents of the drive do not work well. Fortunately, this Rosewill enclosure does not encrypt the contents of the drive. Next, reinstall the original drive into your Bolt. Reassemble the Bolt (helpful instructions are in the video linked above). Connect all cables to your Bolt, EXCEPT the power cable. Do not connect the power cable yet. Connect the eSATA cable to the Bolt and the external HDD enclosure. Connect the power cable to your external HDD, and turn on the HDD. Wait a few seconds for the HDD to spin-up. Finally, connect power to your Bolt. The Bolt will already be configured for external storage (MFS Tools configured it for you). Enjoy your newly expanded storage!