I ran Startup Repair on a fully updated, fresh installation of Win8.1u1 in a Virtual Box VM on 22 Jul 2014
This installation is not associated with a Microsoft Account - it's a local account named "Owner" (without the quotes)

It generated the following 5 files (in the C:\Windows\System32\LogFiles\Srt directory (links are to the text of the files further down the page - there's also a "Top" link there which will bring you back to the top of the page)
-  bcdinfo.txt - 4 kB
-  bootfailure.txt - 1 kB (this is an empty document - likely because the boot didn't fail)
-  bootstat.dat - 66 kB (interestingly, this file was modified 1 hour before the others - and this was before the VM actually existed.  The other times (created/accessed) are the same as the other files - 1 hour later)
-  disklayout.txt - 5 kB
-  SrtTrail.txt - 5 kB

Some info on bootstat.txt here (dates from Vista in 2009):  http://www.geoffchappell.com/notes/windows/boot/bsd.htm
The Windows bootstat.dat file is located in C:\Windows (in Win8.1u1) and is changed (it seems) at each boot

ToDo:
- experiment w/failed boot scenarios
- run Process Monitor boot log w/Startup Repair

XP Recovery Console ISO:  http://www.thecomputerparamedic.com/files/rc.iso
Thanks to hamluis! :  http://www.markharding.com/xp_recovery_cd/recovery.iso

ISO Recorder Power Toy (XP Versions):  http://isorecorder.alexfeinman.com/v2.htm

XP Recovery Console Tutorial:  http://www.bleepingcomputer.com/tutorials/tutorial117.html

Vista Startup Disk (32 bit):
http://coblitz.codeen.org/neosmart.net/downloads/guides/Vista_Repair/Vista_Recovery_Disc_x86.iso

Vista Startup Disk (64 bit):
Unable to locate :0(

Vista Startup Disk (32 & 64 bit versions) - torrent site:
http://neosmart.net/blog/2008/windows-vista-recovery-disc-download/

Vista Startup Disk (32 & 64 bit versions):
http://www.go-vista.de/forum/systemtools/vista-recovery-cd/

ISO Recorder Power Toy (Vista Versions):  http://isorecorder.alexfeinman.com/Vista.htm

Vista Startup Repair Tutorial:  http://www.bleepingcomputer.com/tutorials/tutorial148.html

Here's a link to a more in-depth description of Startup Repair:  http://technet.microsoft.com/en-us/library/cc722188.aspx
Also, it states that the logfile is located at %WINDIR%\System32\LogFiles\Srt\SrtTrail.txt

Startup Repair log:

Startup Repair diagnosis and repair log
---------------------------
Last successful boot time: 8/9/2008 4:34:15 PM (GMT)
Number of repair attempts: 1

Session details
---------------------------
System Disk = \Device\Harddisk0
Windows directory = E:\Windows
AutoChk Run = 0
Number of root causes = 1

Test Performed: 
---------------------------
Name: Check for updates
Result: Completed successfully. Error code =  0x0
Time taken = 0 ms

Test Performed: 
---------------------------
Name: System disk test
Result: Completed successfully. Error code =  0x0
Time taken = 0 ms

Test Performed: 
---------------------------
Name: Disk failure diagnosis
Result: Completed successfully. Error code =  0x0
Time taken = 266 ms

Test Performed: 
---------------------------
Name: Disk metadata test
Result: Completed successfully. Error code =  0x0
Time taken = 31 ms

Test Performed: 
---------------------------
Name: Target OS test
Result: Completed successfully. Error code =  0x0
Time taken = 78 ms

Test Performed: 
---------------------------
Name: Volume content check
Result: Completed successfully. Error code =  0x0
Time taken = 110 ms

Test Performed: 
---------------------------
Name: Boot manager diagnosis
Result: Completed successfully. Error code =  0x0
Time taken = 31 ms

Test Performed: 
---------------------------
Name: System boot log diagnosis
Result: Completed successfully. Error code =  0x0
Time taken = 0 ms

Test Performed: 
---------------------------
Name: Event log diagnosis
Result: Completed successfully. Error code =  0x0
Time taken = 62 ms

Test Performed: 
---------------------------
Name: Internal state check
Result: Completed successfully. Error code =  0x0
Time taken = 0 ms

Test Performed: 
---------------------------
Name: Boot status test
Result: Completed successfully. Error code =  0x0
Time taken = 0 ms

Test Performed: 
---------------------------
Name: Setup state check
Result: Completed successfully. Error code =  0x0
Time taken = 532 ms

Test Performed: 
---------------------------
Name: Registry hives test
Result: Completed successfully. Error code =  0x0
Time taken = 2406 ms

Test Performed: 
---------------------------
Name: Windows boot log diagnosis
Result: Completed successfully. Error code =  0x0
Time taken = 0 ms

Test Performed: 
---------------------------
Name: Bugcheck analysis
Result: Completed successfully. Error code =  0x0
Time taken = 625 ms

Test Performed: 
---------------------------
Name: Access control test
Result: Completed successfully. Error code =  0x0
Time taken = 8797 ms

Test Performed: 
---------------------------
Name: File system test (chkdsk)
Result: Completed successfully. Error code =  0x0
Time taken = 0 ms

Test Performed: 
---------------------------
Name: Software installation log diagnosis
Result: Completed successfully. Error code =  0x0
Time taken = 0 ms

Test Performed: 
---------------------------
Name: Fallback diagnosis
Result: Completed successfully. Error code =  0x0
Time taken = 0 ms

Root cause found: 
---------------------------
Unspecified changes to system configuration might have caused the problem.

Repair action: System files integrity check and repair
Result: Failed. Error code =  0x2
Time taken = 456172 ms