hi, bit of a stunned query here but I usually let windows install that partition, this time I had formatted the partition and windows 10 of course did not create it, so my question is, do I truly need such a partition intact? I think it holds some boot recovery tools or something, if such a partition doesn't exist where does windows hold these files? anywhere else? thanks guys
Google? BitLocker and normally it puts your boot files on it. If the partition isn't being created or used the boot files are instead put on your boot device and BitLocker can't be used. Keep in mind that this partition is only used on MBR formatted drives, GPT has a different layout.
I'm not sure how many partitions you get with MBR, but I have GPT and have first 1 300MB partition and then 1 100MB partition. The 100MB partition is used to place all bootfiles on and actually all files required to boot the operating systems on other partitions. Bitlocker stuff also goes on there, because when you encrypt your complete windows partition you need some way to decrypt it since UEFI won't be able to read it. So you can do some workaround and avoid this partition. The bootfiles can be placed on any partition really. But keep in mind that if you place the bootfiles on your windows partition you won't be able to encrypt it with bitlocker. I think the 300MB partition contains the recovery Winpe. With previous versions you could create a recovery cd from a WinRE.wim image, now this WinRE (= WinPE with recovery stuff in it) lives on a separate partition so you don't need a bootcd anymore.
At least on Windows 7 in MBR/Legacy/BIOS-mode, you don't need the System Reserved partition. You can clean-install Windows without it by using diskpart to wipe the drive out, and then create a primary partition over the entire space, and then install Windows to it (thus leaving you with a Windows install that takes up 1 partition that uses the entire drive).
You can use the "Extend" option in the graphical installer to get rid of the System Reserved partition. You delete one partition first, then extend the other one. I have done this already in Windows 10. There is no need for the System Reserved partition, and there is also no need to use Diskpart to do this.