What does HRESULT 0xC0390002 (ERROR_BCD_TOO_MANY_ELEMENTS) mean?

ERROR_BCD_TOO_MANY_ELEMENTS

ERROR_BCD_TOO_MANY_ELEMENTS identifies this condition: enumerating a BCD object/store exceeded an allowed element threshold, often indicating an unexpectedly large, duplicated, or corrupted configuration set.

Start with the failing layer

BCD repair should begin with an export and an inventory of both BCD objects and firmware entries. Object GUIDs, EFI System Partition paths, referenced device elements, firmware NVRAM capacity, and boot order must be correlated; editing one representation in isolation can create a second inconsistency.

The code does not identify which element is invalid; it states that the enumerated set exceeds the accepted bound.

Preserve before retrying

• Store copy/hash, object GUID, element count by type, and enumeration API
• Duplicate/stale objects, inherited chains, and firmware-generated entries
• Windows build and any management tool that recently rewrote the store
• Whether the count grows after each deployment, imaging, or synchronization cycle

Three useful comparisons

• Enumerate an offline copy with a bounded diagnostic tool.
• Compare against a newly created store for the same machine role.
• Remove only verified stale test entries from a duplicate store and measure the threshold again.

A defensible fix

The corrective action should be narrow: Back up the store, remove provably obsolete duplicates or rebuild from authoritative boot entries rather than truncating enumeration results.

Close the incident only when the cleaned store enumerates completely, boots every retained entry, and repeated servicing no longer increases element count.

Technical references

• Microsoft Open Specifications: HRESULT values.
• Microsoft: boot options in Windows.
• Microsoft: BCDEdit command-line options.
• Microsoft: BcdStore class.