What is the 100mb partition Windows 7 SOMETMES creates on install?

[Cyber Akuma]

Windows 7 sometimes automatically asks to create a 100mb partition for system files on startup.

Can anybody tell me just what exactly this partition is? Whats on it? And why sometimes it creates it, and sometimes it doesn't? I've installed Windows 7 on a few systems now, and it seems to be random, what causes it to install and to NOT install this partition? And whats on it? Would it be better to have this partition or not?

Would upgrading from a previous version of Windows but doing a clean install create this partition?

How about installing on a drive that already has existing partitions?

 

[bigdogchris]

I think it has the recovery tools on it, as well as the windows memory diagnostic tools. You can assign it a drive letter and browse and see what's all there.

 

[JonathanJ]

The partition contrains recovert tools, boot files, and enables encryption for bitlocker.

 

[Tawnos]

As for the when... If you already have formatted and partitioned, it will not be created. If you are upgrading, it will not be created. If you're installing fresh, it will be.

 

[JimmiG]

I think it has the recovery tools on it, as well as the windows memory diagnostic tools. You can assign it a drive letter and browse and see what's all there.

Which is pretty nice actually - no need to find a Windows DVD when you need to access those tools. Though I prefer to keep it hidden in Windows by not assigning a drive letter.

 

[Tawnos]

Which is pretty nice actually - no need to find a Windows DVD when you need to access those tools. Though I prefer to keep it hidden in Windows by not assigning a drive letter.

Which is the default, unless you were pirating leaked versions and happened to get one that had a build to build issue where the drive was given a letter.

 

[Ranma_Sao]

Both the partition length and partition start address are stored as 32-bit quantities. Because the block size is 512 bytes, this implies that neither the maximum size of a partition nor the maximum start address (both in bytes) can exceed 232 × 512 bytes, or 2 TiB. Alleviating this capacity limitation is one of the prime motivations for the development of the GUID Partition Table (GPT).

Stolen from Wikipedia. The whole reason for a 100MB boot partition, is to guarantee the system can boot.

If you have a 4TB single partition formatted, the MBR can't deal with a partition that big. If the machine is an upgrade, Windows knows it already could boot before, if it's a new install, it creates it to be on the safe side...

This posting is provided "AS IS" with no warranties, and confers no rights.

 

[Cyber Akuma]

Both the partition length and partition start address are stored as 32-bit quantities. Because the block size is 512 bytes, this implies that neither the maximum size of a partition nor the maximum start address (both in bytes) can exceed 232 × 512 bytes, or 2 TiB. Alleviating this capacity limitation is one of the prime motivations for the development of the GUID Partition Table (GPT).

Stolen from Wikipedia. The whole reason for a 100MB boot partition, is to guarantee the system can boot.

If you have a 4TB single partition formatted, the MBR can't deal with a partition that big. If the machine is an upgrade, Windows knows it already could boot before, if it's a new install, it creates it to be on the safe side...

This posting is provided "AS IS" with no warranties, and confers no rights.

Quite a detailed an informative post, thank you

So basically you only need it if you are installing it on a drive over 2 Terrabytes and the system dosen't support GUID?