Safe to delete SoftwareDistribution folder(s)? And how?

Included as part of this tutorial if you're planning to reset Windows Update and lose your Update History
Reset Windows Update in Windows 10 | Tutorials

I have .bak, no other such.

There are numerous reasons why upgrading may fail. Noting any error messages may help, as may ensuring you have enough free space on disk (e.g. 30Gb on C: ), your disk partition and file structure are sound, removing any conflicting security solutions or programs, disconnecting unnecessary peripherals.

You can also examine the various log files.

Try downloading the iso, then manually upgrading without accepting updates.

Many useful tips and guides from the links and subsequent linked documents from here:
Resolve Windows 10 upgrade errors

Thanks for the quick reply dalchina.
Looking at the code, i can see that ive tried at least some of the fixes that the bat also executes, like the renaming of catroot and softwaredistibution folders and start / stopping the windows update components, without any success. But ill probably give this a try aswell. But i guess the required fix is different compared to which issues you're getting, so not sure if this is the fix thats required.
Now that ive had my windows update history deleted, i cant see all the pervious error messages, and currently i only got 1 listed which is the 0xc1900101 error. This has probably been the one ive seen the most (i think, not sure), but im sure there had also been other errors involved.

EDIT:
I also tried installing with all, or at least all that i could find, anti-virus / malware / cleaner programs removed, all cables removed except, keyboard, mouse, monitor, ethernet and also with at least 45 gb space, but didnt make any difference. Not sure if its a driver incompatibility or what. Currently im quite low on space, at around 25 gb, but again, the softwaredistribution folders are taking up 23,3 gb at the moment.
It can be pretty hard to tell if there is a driver incompatibility though, as im really not sure what to look for concerning this, or what could cause it.

I have always deleted the SoftwareDistribution.bak, bak1 etc folders [using an Admin account] without any problems. Their permissions are set up to allow this - owned by System but with Full control for Admins.

My SoftwareDistribution.bak folders are capitalised as shown. If yours are lowercase then I'd suspect you have previously used a script to reset WU and that script created the bak folders but did not bother about capitalising the name.

If you are concerned about deleting the bak, bak1 folders then make a system image before you start so that you can get back to square one later if you want to.

Denis

From the link I posted, which I'd encourage you to look at:
a. Note any error messages and research them
b. Inspect log files for clues:
Log files - Windows IT Pro | Microsoft Docs

Resolve Windows 10 upgrade errors - Windows IT Pro | Microsoft Docs
On the left is a sort of index.

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The table at the Microsoft site below lists the most common upgrade and installation errors, and a few things you can try to fix the problems.

Get help with Windows 10 upgrade and installation errors - Windows Support

Resolve Windows 10 upgrade errors

The Windows 10 upgrade process: An explanation of phases used during the upgrade process.

Quick fixes: Steps you can take to eliminate many Windows upgrade errors.

Upgrade error codes: The components of an error code are explained.

• Result codes: Information about result codes.
• Extend codes: Information about extend codes.

Log files: A list and description of log files useful for troubleshooting.

• Log entry structure: The format of a log entry is described.
• Analyze log files: General procedures for log file analysis, and an example.

Resolution procedures: Causes and mitigation procedures associated with specific error codes.

• 0xC1900101: Information about the 0xC1900101 result code.
• 0x800xxxxx: Information about result codes that start with 0x800.
• Other result codes: Additional causes and mitigation procedures are provided for some result codes.
• Other error codes: Additional causes and mitigation procedures are provided for some error codes.

Before you get started installing Windows 10, be sure that you disable Secure Boot and Fast Boot in your UEFI firmware settings. Some motherboards do not support booting from a USB flash drive with these enabled.

Once installation has finished, you can enable Secure Boot and Fast Boot again if you like.

from
Upgrade to Windows 10 | Tutorials

Start with any error message displayed on the screen as part of the failed upgrade procedure. Copy the exact text, then search using that, or part of it.

Likewise with anything that looks indicative from the logs.

You're looking for a post where such a problem has been encountered.
Also post a screenshot of your partitions using Minitool Partition Wizard (free) making sure all text is visible.

I expect a member called @zbook will be along soon with a standard post which asks you to collect and post a lot of data.

That looks ok for a MBR installation. Without the initial error message or other information, it's not possible to comment further. I've mentioned the idea of a manual upgrade using an iso, but that won't 100% guarantee success of course.