Hi Hmm888:
Just an FYI that new legacy CCleaner v6.40.11558 builds (rel. 16-Apr-2026) are now available posted on the official CCleaner builds download page. This includes the standard Win 7 / 8.x “sunset” installer (ccsetup640_win7.exe) as well as a new CCleaner Portable v6.40.11558 build (ccsetup640.zip) . Release notes are posted <here> and state “This release focuses on fixing update and connection issues affecting users on older versions of Windows”.
According to RENOP01’s 29-Apr-2026 topic 0x6 the handle is invalid. Suggested fix does not work. Can not update to 6.40.11558 On a Win 11 PC users might see a “0x6 the handle is invalid” error when trying to run the standard .exe installer on a newer Win 10 and/or Win 11 machine.
I keep a copy of CCleaner Free Portable v6.39.11548 (rel. 20-Aug-2025) on a removable USB stick that I use for comparative testing with other disk cleaners and it still appears to be running correctly on my Win 10 machine, although I only use the Custom Clean feature (i.e., I never use Health Check, Software Updater, etc.). I haven’t tested the new CCleaner Free Portable v6.40.11558 yet to see if it runs correctly on my Win 10 machine.
Dell Inspiron 15 5584 * 64-bit Win 10 Pro v22H2 build 19045.7184 * Firefox v150.0.1 * Microsoft Defender v4.18.26030.3011-1.1.26030.3008 * Malwarebytes Standard v5.5.4.252-154.0.5578 * Macrium Reflect Free v8.0.7783 * CCleaner Free Portable v6.39.11548 * HDCleaner Portable 64-Bit v2.095