The short version
- 01Restart the device and run setup again, which is Microsoft's first and usual remedy.
- 02Choose Restart rather than Shut down, since fast startup can skip the pending work.
- 03Run Disk Cleanup if restarting does not help, and clean up temporary files.
- 04Use the system files option in Disk Cleanup, which is where previous installations appear.
- 05Retry the upgrade once the cleanup has finished and the machine has restarted again.
- 06Check free space before retrying, since an upgrade needs about 20 GB on a 64-bit system.
Raw message
0xC1900107 MOSETUP_E_CLEANUP_PENDING
Likely causes
- A cleanup operation from an earlier installation attempt that has not finished.
- A restart the machine has been waiting for and never received.
- Temporary and system files left behind by a previous upgrade attempt.
- A machine that sleeps rather than shutting down, so the pending work never runs.
What 0xC1900107 means
Microsoft's description is unusually plain for a setup code: a cleanup operation from a previous installation attempt is still pending, and a system reboot is required in order to continue the upgrade. In the setup platform's own error list the same code appears as MOSETUP_E_CLEANUP_PENDING.
So nothing is broken. An earlier attempt at this upgrade — successful or not — left work that Windows can only finish while it is restarting, and setup will not begin a new attempt until that work is done. It is a queue, not a fault.
That makes this one of the cheapest Windows errors to resolve, and it is worth trying the simple thing before reading any further.
Restart properly, then try again
Microsoft's remedy is to restart the device and run setup again. Do that first, and give it time — the pending cleanup happens during the restart, so a machine that takes longer than usual to come back is doing exactly what you want.
Choose Restart rather than Shut down. On Windows, shutting down and powering on again is not always equivalent to a restart, because fast startup saves part of the system state instead of tearing it down. A restart always performs a full cycle, which is what the pending operation needs.
If the machine is normally closed rather than shut down, it may not have had a true restart in weeks. That is the usual explanation for this code appearing on a laptop that otherwise seems perfectly healthy.
When a restart is not enough
Microsoft's follow-up is specific: if restarting the device doesn't resolve the issue, use the Disk Cleanup utility to clean up the temporary files and the system files. The second half matters — the option to clean up system files is a separate button in Disk Cleanup, and it is the one that reaches previous Windows installations and leftover setup files.
That leftover material is both the cause and a side benefit of removing it. A previous upgrade attempt can leave many gigabytes behind, and clearing it addresses the pending cleanup and the free space an upgrade needs at the same time.
It is worth checking the space before retrying. Microsoft's figures for the related space errors are 16 GB free for a 32-bit installation and 20 GB for a 64-bit one, and an upgrade that starts without room will fail again for a different reason.
Sources and review notes
Checked on . Based on Microsoft's Windows upgrade resolution procedures, which is where the cause, the restart instruction, the Disk Cleanup follow-up and the free-space figures come from. The distinction between Restart and Shut down under fast startup is editorial. Glitchary is independent of Microsoft.