Windows upgrade error 0xC1900101

• Estimated time: 3 min
• Easy
• Low risk

The extended code and recent changes prevent blind retries.

1. Wait for rollback to finish and Windows to respond. Record current/target version, model, full code such as 0xC1900101-0x20017, phase/operation if shown and recently changed hardware/drivers. Do not clean installation temporary files yet: they may contain diagnostic records.

2. If no suffix appears, still keep the time and upgrade method. A missing extended code does not justify choosing a random driver; follow visible devices or SetupDiag.

• Estimated time: 5 min
• Easy
• Low risk

1. Open Device Manager and the properties of the entry with a warning. Keep Device status/code, name, provider, driver version and date. Code 43 or Code 10 has its own diagnosis; follow the related guide before repeating the Windows upgrade.

2. If there are no warnings, compare with the date of a new driver or hardware change. That timing prioritizes investigation but does not prove blame. Without a clear change, do not update everything: move to the SetupDiag report.

• Estimated time: 5 min
• Easy
• Low risk
• Restart required

1. After rollback finishes, save work and eject removable storage before disconnecting it. Remove only nonessential accessories such as a printer, capture device or dock; retain keyboard, mouse, display, power and required access. Do not remove internal drives or disconnect during Setup.

2. If retrying, do so once with backup and stable power, without changing other drivers simultaneously. If it completes, the external group or its software warrants review; it does not identify which accessory. Reconnect one at a time after upgrading, checking operation and official compatibility without causing new rollbacks to prove it.

3. If it fails identically, preserve that attempt’s logs and move to SetupDiag. Do not keep removing essential devices by elimination.

• Estimated time: 5 min
• Easy
• Low risk

1. Open %WinDir%\Logs\SetupDiag\SetupDiagResults.xml if it exists and matches the recent attempt. SetupDiag analyzes setup logs; it can report the phase, last operation and matching rule. Not naming a file does not rule out drivers.

2. If it names a driver/package or specific blocker, move to targeted correction. If it only reports rollback, preserve setupact.log and setuperr.log from that attempt’s Panther/Rollback folders under $Windows.~BT\Sources; do not delete the last mentioned file: it may be affected rather than causal.

3. The phase narrows what to inspect but does not identify a part alone. In Windows 10 documentation, 0x20017 points to SafeOS boot and 0x30018 to device installation; setupapi.dev.log can add detail for the latter. Use the actual phase and target-version documentation rather than applying old Citrix examples to a PC without it.

4. If the report is missing or insufficient, the manual run below can analyze preserved logs. If there is still no identified driver, send the set to Microsoft/OEM through a private channel instead of deleting drivers.

• Estimated time: 5 min
• Easy
• Low risk
• Restart required

1. Compare the indicated .sys file, .inf package or device with its properties: provider, version and hardware identifier. If the report cannot safely map them, ask OEM/IT to identify them. A similar-looking name online is insufficient grounds for uninstalling it.

2. Prioritize storage/disk controller if logs point to boot or that driver; display if they name its package; networking if they name its adapter/filter. Category alone does not prove fault. Look for a version supported for the model and target Windows version through Windows Update or the official OEM/vendor.

3. If failure began after changing that driver and a compatible previous version exists, targeted rollback may be preferable to another random version. Before changing it, keep a backup, compatible installer and a way to recover access. Do not remove storage, encryption or managed-network drivers without the manufacturer/IT’s specific procedure.

4. After correction and required restarts, retry once and compare code/phase. If it completes, stop. If identical, provide both results; if a different blocker appears, follow that new finding. Do not use third-party driver updaters.