Gptgen is a command line tool for converting hard drives partitioned according to the MSDOS – style "MBR" scheme to the GPT (GUID partition table) partitioning scheme, while retaining all of data on the hard disk. Since it is a command line tool, you cannot double-click it in order to start it after downloading.
On Windows OS, like Windows 7 or Windows 10, you need to type "gptgen [-w] \\.\physicaldriveX" in command line prompt according to its "readme" instruction, where X is the disk number that you want to convert. The [-w] option makes Gptgen write the generated GPT to the disk, otherwise the primary table will be written to a file named "primary.img", and the secondary table to "secondary.img", in the directory that the program was invoked from. All of them ensure that you can convert MBR to GPT without data loss using Gptgen.
Why convert MBR to GPT?
Generally speaking, MBR scheme has partition number limitation of 4, which means you can only create up to 4 primary partitions. Primary partitions have boot block comparing to logical partition, so if you want to install more than two operating systems in your PC, you need to convert logical to primary. GPT partitioning scheme on the other hand almost has no limitation of primary partition number because every partition in GPT scheme has been set as “Primary” and you can create up to 128partitions. What’s more, MBR scheme disk supports the capacity up to 2 TB. Any disk that beyond 2 TB will be turned into unallocated space after the partition and you cannot make use of it from any method.
Why need Gptgen alternative?
Gptgen is a handy converting tool but it requires more knowledge on command line operation. It is not a common utility for most PC users since it has no graphical user interface. It is more likely designed for advanced users. Moreover, you cannot see additional unallocated space after conversion using Gptgen according to its users’ feedback. It also doesn’t support dynamic disk, which is inconvenient in computer management nowadays. Further, the last update of Gptgen could back to 3 years ago, so you hardly find tech support from their team.
The alternative to Gptgen - AOMEI Partition Assistant Professional is a professional partition manager that allows converting MBR to GPT disk without losing data. It has a clean and user-friendly interface, you can manage that process easily even you are new to computer field. It supports dynamic disk, RAID disk as well. The most important thing is you can make use of the unallocated space directly after conversion using AOMEI Partition Assistant. Download its demo version and have a try.
3 Easy steps: convert to GPT via AOMEI Partition Assistant
If you convert system or boot disk to GPT, make sure that your motherboard supports EFI/UEFI boot (read motherboard’s user manual). If not, then stop converting, otherwise your system would likely unable to boot next time.
Step 1. Install and launch Partition Assistant Pro. Pitch on the disk you want to convert, right click it and select "Convert to GPT" in the left pane.
Step 2. Click "OK" -> "Yes" in the pop-up window.
Step 3. Now the disk has changed to GPT, click "Apply" to make it real.
①For system boot disk conversion between MBR and GPT styles, to guarantee system bootable, you need to enter BIOS and change the boot mode after the conversion is completed.
②To convert disk that doesn’t contain Windows OS, you can use its free edition AOMEI Partition Assistant Standard.
As Gptgen alternative, AOMEI Partition Assistant has many other powerful features. For example, you can transfer OS to new hard drive when you want to update the old disk. If you are using Windows 10 or Windows 8, you are capable of creating Windows to go USB with it even the Windows OS is not enterprise version.