The message is not meaningless. The system is trying to protect your computer from a damaged or malicious file.
A system file has been corrupted, if a message from Windows(r) File Protection is appearing telling you a file needs to be replaced. If you still have the dllcache folder intact, you can:
1. Open C:\Windows\system32\dllcache from the Run box (available through pressing Win + R on your keyboard).
2. Download Replacer.
3. Copy the file from dllcache that you want to replace to your desktop
4. Rename the file (for instance, to name a really common one, from SHELL32.DL_ to shell32.dll).
5. Open C:\Windows\system32 and locate the other file.
6. Drag it in and press Enter.
7. Drag in the new file and press Enter.
8. Reboot the PC.
If this fails, or if it is several files, your PC is infected and needs cleaning. Download Microsoft(r) Security Essentials, McAfee(tm) Security Scan, or a trial version of Norton(tm), and throughly scan your PC. This should fix your file integrity issues.