Most people delete SrtTrail.txt or ignore it. Technicians read it first, because Startup Repair writes down everything it tested and - when it can - the exact file or fault that broke the boot. This page shows you where the log lives, how to open it when Windows will not start, and how to read its verdict.
When Automatic Repair fails, it leaves a written report behind: SrtTrail.txt. Reading it takes two minutes and tells you whether you have a five-minute repair or a restore job. The skill is knowing which lines matter. The log is long and repetitive by design - it lists every test, one after another - but the answer sits in two places: the Root cause found section near the end, and the pattern of which tests failed. Here is how to reach the file and read both.
diskpart, then list vol, note the letter of the large Windows partition, then exitnotepad C:\Windows\System32\LogFiles\Srt\SrtTrail.txtcopy C:\Windows\System32\LogFiles\Srt\SrtTrail.txt E:\ - use your USB drive's letterThe top of the log quietly prevents a classic mistake. Session details records the System Disk and the Windows directory that repair examined. Confirm they point at your real Windows installation. On multi-disk PCs, repair occasionally examines the wrong disk, and every later test is then meaningless. This section also shows the number of repair attempts - if it says repair has already tried many times across many restarts, you have your first honest signal: this fault is not one Startup Repair can fix, because it has already had its chances.
This is the verdict, and it comes in three forms. A named corrupt file - typically a boot-critical driver ending in .sys - means one component is damaged; replacing that file or rolling back its driver or update can end the loop, and this is the one case where repair commands genuinely work. A named registry or boot fault means the configuration is damaged; a restore point or an image restore is the proportionate answer. No root cause found - the log's honest admission that the tests passed or were inconclusive while Windows still will not boot - means the damage is below the tests: failing disk hardware, deep file-system damage, or corruption spread across many files. Each of these three verdicts routes you to a different case page in this guide, which is exactly what a diagnosis is for.
Between the header and the verdict, the log lists every test with a result and an error code. Tests ending with Error code = 0x0 passed. You are scanning for the tests that did not - disk tests, boot configuration tests, registry tests - because a failed category corroborates the verdict. One caution about reading this evidence honestly: a test that fails once can be a symptom, not the cause. A disk test failing because the disk is dying, for example, will also make file tests fail downstream. Read the log for the earliest, simplest failure, and treat everything after it as possible fallout. And note what the log cannot do: it only reports on what Startup Repair tested. It is a good witness, not an all-knowing one - which is why the next step after reading is a decision, not automatically another command.
See the whole recovery in the video - from the SrtTrail error screen to a laptop booting again after the Macrium Reflect clone restore.
Watch Full VideoThe file sits at C:\Windows\System32\LogFiles\Srt\SrtTrail.txt on your Windows partition. Inside the recovery environment the same partition often carries a different drive letter, commonly D:, which is why the repair screen may show the log path with a different letter. Use diskpart and list vol to confirm the letter before opening it.
It means Startup Repair's tests could not pin the failure on one component, even though Windows clearly cannot boot. In practice this points at damage the tests do not isolate well: a disk that is beginning to fail, widespread file corruption, or several small faults together. Treat it as a decision signal - stop repeating repairs and move to the restore route, or to data rescue if you have no image.
Yes. The log remains on disk at the same path, so you can open it in Notepad from normal Windows and review what repair found. It is worth saving a copy if the same PC has looped before - comparing two logs from two incidents often reveals a repeating culprit, such as the same driver file named twice.