"Couldn't update to Windows 8.1 - 0xC1900101 - 0x40017"

Many people have already suggested these exact steps, thanks anyway,

I'm getting the same error and after looking at the logs, I'm guessing it is because somewhere in the upgrade process, it ASSUMES that C: is your boot drive, which mine isn't.  It's looking for the boot files on C: and can't find them.  Nice one.

2013-10-26 05:01:47, Info                  SP     Attempting to reset setup.

2013-10-26 05:01:47, Info                  SP     The system will now restart.

2013-10-26 05:01:47, Info                  SP     Persisting diagnostics data to C:$WINDOWS.~BT\Sources\Diagnostics\diagnostics.dat

2013-10-26 05:01:47, Info                  SP     Diagnostics data saved successfully

2013-10-26 05:01:47, Info                  SP     Recovery succeeded. Rollback will now restart the machine.

2013-10-26 05:04:12, Info                  SP     Initializing diagnostics helper; data file = C:$WINDOWS.~BT\Sources\Diagnostics\diagnostics.dat

2013-10-26 05:04:12, Info                  SP     Found existing diagnostics data, attempting to load it.

2013-10-26 05:04:12, Info                  SP     Rollback: Showing splash window

2013-10-26 05:04:12, Info                  SP     Rollback: Attempting recovery first.

2013-10-26 05:04:12, Info                  SP     Current phase string : FirstBoot,End

2013-10-26 05:04:12, Info                  SP     Current op string    : NULL

2013-10-26 05:04:12, Info                  SP     Current result string: NULL

2013-10-26 05:04:12, Info                  SP     Current bugcheck string: NULL

2013-10-26 05:04:12, Info                  SP     Connected standby str: No

2013-10-26 05:04:12, Info                  SP     Connected standby    : No

2013-10-26 05:04:12, Info                  SP     Current phase : 4

2013-10-26 05:04:12, Info                  SP     Current op    : 23

2013-10-26 05:04:12, Info                  SP     Current result: Unknown

2013-10-26 05:04:12, Info                  SP     Bugcheck code : 0x9DE9E1E6

2013-10-26 05:04:12, Info                  SP     Maximum recovery attempts reached.

2013-10-26 05:04:12, Info                  SP     Not attempting to recover system in C:\WINDOWS

2013-10-26 05:04:12, Info                  SP     SetupPlatfrom: Executing Execute.PreRollback commands

2013-10-26 05:04:12, Info                  IBSLIB RollbackReinitialize in progress...

2013-10-26 05:04:12, Info                  IBSLIB RollbackReinitialize finished.

2013-10-26 05:04:12, Info       [0x064149] IBSLIB RollbackExecuteSequence in progress...

2013-10-26 05:04:12, Info       [0x064130] IBSLIB ExecuteRollbackSequence: Checkpoint(SetupPlatformOnlineApplyCheckpoint) rollback in progress.

2013-10-26 05:04:15, Info       [0x064131] IBSLIB ExecuteRollbackSequence: Checkpoint(SetupPlatformOnlineApplyCheckpoint) rollback finished.

2013-10-26 05:04:15, Info       [0x064130] IBSLIB ExecuteRollbackSequence: Checkpoint(SetupPlatformOSSwitchCheckpoint) rollback in progress.

2013-10-26 05:05:39, Info                  IBSLIB OSRollbackService::CCheckpoint::MoveOrCopyDirectory: source path "C:\WINDOWS\Minidump" does not exist; ignoring

2013-10-26 05:05:39, Info                  IBSLIB OSRollbackService::CCheckpoint::MoveOrCopyFiles: Moving/copying memory.dmp from C:\WINDOWS to C:$WINDOWS.~BT\Sources\Rollback

2013-10-26 05:05:39, Info                  IBSLIB OSRollbackService::CCheckpoint::ExtractCrashDump: Found page file at C:\pagefile.sys; attempting to extract crash dump

2013-10-26 05:05:39, Info                  IBSLIB OSRollbackService::CCheckpoint::ExtractCrashDump: Pagefile at C:\pagefile.sys did not contain a crash dump.

2013-10-26 05:05:39, Info                  IBSLIB OSRollbackService::CCheckpoint::MoveOrCopyFiles: Moving/copying setupapi*.log from C:\WINDOWS\inf to C:$WINDOWS.~BT\Sources\Rollback\setupapi

2013-10-26 05:05:39, Info                  IBSLIB OSRollbackService::CCheckpoint::MoveOrCopyFiles: Moved C:\WINDOWS\inf\setupapi.app.log to C:$WINDOWS.~BT\Sources\Rollback\setupapi\setupapi.app.log

2013-10-26 05:05:39, Info                  IBSLIB OSRollbackService::CCheckpoint::MoveOrCopyFiles: Moved C:\WINDOWS\inf\setupapi.dev.log to C:$WINDOWS.~BT\Sources\Rollback\setupapi\setupapi.dev.log

2013-10-26 05:05:39, Info                  IBSLIB OSRollbackService::CCheckpoint::MoveOrCopyFiles: Moved C:\WINDOWS\inf\setupapi.offline.log to C:$WINDOWS.~BT\Sources\Rollback\setupapi\setupapi.offline.log

2013-10-26 05:05:39, Info                  IBSLIB OSRollbackService::CCheckpoint::MoveOrCopyDirectory: MoveFile(from "C:\WINDOWS\system32\logfiles\scm" to "C:$WINDOWS.~BT\Sources\Rollback\scmlogs") succeeded.

2013-10-26 05:05:39, Info                  IBSLIB OSRollbackService::CCheckpoint::MoveOrCopyDirectory: MoveFile(from "C:\WINDOWS\system32\winevt\logs" to "C:$WINDOWS.~BT\Sources\Rollback\evtlogs") succeeded.

2013-10-26 05:05:39, Info                  SP     CSetupPlatformOSSwitchCheckpoint::Rollback: Quarantine log file exists; proceeding with QuarantineRollback

2013-10-26 05:05:39, Info                  SP     CSetupPlatformOSSwitchCheckpoint::Rollback: Attempting to remove file C:\BOOTNXT

Note that my $WINDOWS.~BT folder is on S: not C:

A full install of 8.0 deleting all my content, updating, then installing 8.1 finally worked for me(read on, because that's not the full story)!  Second tier Microsoft tech worked some overtime to get me through this process.  What I realized in this process, however, is that I may not have the same error as you all (mine ends in 0x20017 - after the blue screen 0000017 we all get). 

This was one heck of a tough nut to break.  I had previously tried reinstalling Windows 8, and that actually failed on me.  The tech had to see that one for himself before he would believe me...ha!  Interesting note that I didn't know until I tried it is that refreshes and resets on an upgraded copy of 8.0 do not work (because you don't have the media).  Saying that, even using the Windows 7 upgrade tool to download 8 and install it myself did not work - failed hard during install (this was what surprised the tech when I showed him).

I know the tech ultimately ran a completely different setup program from anything I had run to get the fresh 8.0 install to take (it runs full screen - looks different than the standard downloaded version - perhaps he mounted the ISO and ran it from there?  Not sure...).  I'm going to try to get the location from him when he calls back tomorrow and report back here for you all (he had to go home for the day, so he is going to find out the status of my PC tomorrow).

I was one of the people that tried EVERYTHING, and I mean EVERYTHING, and nothing worked on my gaming computer.  After finding GameSave Manager, and finding out that Steam recovers your games for you (assuming they are installed on a separate drive), I was less hesitant to wipe completely (which I swore before I wouldn't do), and if you have my problem, there is no other solution.

The story here is that Microsoft has absolute best in class customer service (he even said if we didn't get this resolved, he was going to try to get me physical media of 8 Pro with MC (full version) free of charge).  While I'm not impressed at this massive debacle with the 8.1 upgrade that cost me 10s of hours of pointless hackery and frustration, kudos to the stellar customer service that was willing to spend hours each day (even on the weekend) working on this.

For the last week I have been having the same problems as have been listed here and tried just about all the suggestions mentioned in the various posts. Out of frustration I lugged my desktop ( a bits and pieces machine)  up to the room where my modem/router is and connected it by Ethernet cable and disabled the wireless connectors, I also connected my old cabled mouse and keyboard and disconnected my wireless mouse/keyboard. HEY PRESTO the update worked after nearly 20 attempts using the wireless connection it work first time with the wired connection. The strange thing is all the wireless connections worked 100% after the update finished ( It does take a long time) without having to update any drivers and a Dell printer which had always refused to work with Windows 8 installed perfectly in Windows 8.1 just by plugging in the USB connector. I hope this experience might be of help to someone but why the install wouldn't work over a wireless connection when all the drivers were correct puzzles me.