Isdone.dll Crc Check Error May 2026

I checked system files. isdone.dll was present. Modified seven years ago—except the date didn't exist. February 29th on a non-leap year.

Then the cursor moved. Half a pixel. Just once. isdone.dll crc check error

I renamed the file. It reappeared in three seconds. I deleted it. The recycle bin showed an error: "Item is already in use." By what? Task Manager showed nothing. No processes. No handles. I checked system files

Just done.