Unable to use windows backup. VSS error?

What about the event logs errors? Is there any lead we have on that?

If you have a system reserved use Disk Management see how much free space you have. If less than 50MB you may have problems here.

My disk management function lists that I have a SYSTEM RESERVED, which is 100mb, and an unnamed partition also recorded as a recovery partition. But I hope to solve the error directly. Again, is there any lead on this warning in the event log:

Volume Shadow Copy Service warning: VSS was denied access to the root of volume \\?\Volume{626d6c76-fa1e-11e0-9ba2-0811961be35c}\. Denying administrators from accessing volume roots can cause many unexpected failures, and will prevent VSS from functioning properly. Check security on the volume, and try the operation again.

Operation:
Removing auto-release shadow copies
Loading provider

Context:
Execution Context: System Provider

And this error:

Volume Shadow Copy Service error: An internal inconsistency was detected in trying to contact shadow copy service writers. The Registry Writer failed to respond to a query from VSS. Check to see that the Event Service and Volume Shadow Copy Service are operating properly, and please check the Application event log for any other events.

Operation:
Gathering Writer Data
Executing Asynchronous Operation

Context:
Execution Context: Requestor
Current State: GatherWriterMetadata

Any help please? :0