Qc1051deu-x64.exe [extra Quality] -

Based on technical naming conventions and common driver repository data, Qc1051deu-x64.exe is a specific Lexmark printer driver installer

"File is not a valid Win32 application": This usually means you are trying to run a 64-bit file on a very old 32-bit version of Windows, or the download was corrupted. Re-download the file.
Camera not found: Ensure no other application (like Zoom or Teams) is using your webcam while the Postident software is trying to start.

Source verification: Because filenames are not trustworthy indicators of origin, always obtain executables from the vendor’s official site or a reputable distributor. Downloading unknown executables risks malware, trojans, or unwanted bundled software.
Digital signatures: Legitimate vendor installers are often code-signed. Check file properties → Digital Signatures in Windows, or use tools like signtool to verify the signer and certificate chain.
Hash checking: Vendors sometimes publish SHA256 or MD5 checksums for downloads; comparing a file’s hash to the published value confirms integrity and that the file wasn’t tampered with.
Antivirus/endpoint scanning: Scan any downloaded executable with up-to-date antivirus software or submit it to multi-engine scanners (e.g., VirusTotal) if you have doubts; note that false positives can occur.
Execution privileges: Installers typically require elevated privileges (UAC). Be cautious granting admin rights to unsigned or unknown installers.