📎 AI Summary:
The thread centers on whether unexpected `.tmp` files in `C:\Windows\System32` (with an `OLD` prefix) are suspicious and why Windows would create them there. The responses explain that `.tmp` files are temporary working files used by Windows or installed components during processes like updates, driver installs, or recovery, and that occasional leftovers can remain if cleanup is incomplete. Overall sentiment is reassuring: contributors advise scanning with antivirus and optionally deleting them if Windows permits, with suspicion mainly warranted if the files keep reappearing or the system shows unusual behavior.
luants30051991

luants30051991

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Thread Author #1
What are these files? Why does Windows need them? I find it suspicious.
 

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Solution
WindowsForum AI
Great question! Here’s what you’re seeing:
  • These files (e.g., OLD551F.tmp, OLD5530.tmp, OLD54FF.tmp) are .tmp files located in the C:\Windows\System32 folder.
  • The .tmp extension stands for "temporary file." They are typically created by Windows or various programs as working files—like scratchpads—while a process is running.
Why are they in System32?
  • Most .tmp files should usually be in your user’s Temp folder, but sometimes system processes or updates might create temporary files in System32, especially during system maintenance, updates, driver installations, or recovery operations.
  • The "OLD" prefix could suggest they’re remnants from an old process, maybe a Windows update or system tool that didn’t clean up...
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WindowsForum AI

WindowsForum AI

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#2
Great question! Here’s what you’re seeing:
  • These files (e.g., OLD551F.tmp, OLD5530.tmp, OLD54FF.tmp) are .tmp files located in the C:\Windows\System32 folder.
  • The .tmp extension stands for "temporary file." They are typically created by Windows or various programs as working files—like scratchpads—while a process is running.
Why are they in System32?
  • Most .tmp files should usually be in your user’s Temp folder, but sometimes system processes or updates might create temporary files in System32, especially during system maintenance, updates, driver installations, or recovery operations.
  • The "OLD" prefix could suggest they’re remnants from an old process, maybe a Windows update or system tool that didn’t clean up after itself.
Should you be suspicious?
  • .tmp files alone aren’t inherently suspicious, but you’re right to check! If you:
  • Didn’t recently run updates or install software,
  • Notice unusual system behavior,
  • Or if these files keep reappearing after deletion,
It’s good practice to scan them with your antivirus to rule out anything malicious.
Safe to delete?
  • In most cases, .tmp files in System32 are safe to delete—especially if their modification dates are old and no program is currently using them.
  • If you try to delete a file that’s in use, Windows will prevent it, so it’s generally safe.
Recommendation:
  • Run a quick scan with your antivirus on those files.
  • Try deleting them—if Windows allows it, you’re good.
  • If you notice new .tmp files constantly showing up or any strange system issues, let us know!
Let me know if you want guidance on checking these files more thoroughly, or if you spot any unusual behavior after cleaning them up.
 

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