r/techsupport • u/AnotherVettel • 2h ago
Solved My PC kept 'freezing' for weeks. I formatted it, swapped the hardware, updated the BIOS... it was a $1 switch inside the mouse (Logitech G502). Here's the full saga to help you.
My PC started freezing at random, out of nowhere, with no trigger. A full clean install of Windows didn't fix it. Worse: almost every fix I tried seemed to work for a few days... and then the problem came back. After weeks of ruling out suspects (RAM, disk, drivers, Explorer, two keyboards, two mouses, USB ports, BIOS, background software), I found out the middle-click switch on my Logitech G502 was firing phantom clicks on its own. Each phantom click triggered auto-scroll, which captures the mouse for the foreground window... every other window went "dead," looking exactly like a system freeze. Fix: disabled the middle button in the mouse's onboard profile.
Consider this a guide for everyone out there chasing a 'random freezing' problem, ruling out suspect after suspect and finding nothing, who, like me, never once thought to suspect the mouse. I used IA to help me describe everything.
How it started:
One day the PC simply began "freezing" at random. No new hardware, no new software, no update I could tie it to, nothing had changed. It would lock up out of nowhere, sometimes for a few seconds, sometimes longer, and then go back to normal as if nothing had happened. No pattern: it could happen twice in an hour, or not at all for days.
My first assumption was the usual one: "Windows is broken somehow". So I went nuclear early: a full clean install. Wiped the drive, reinstalled everything from scratch.
The problem survived the clean install. In hindsight, that was the loudest clue in the whole case so far.
The symptoms, in detail.
If you're searching for something similar, here's the exact fingerprint. During a "freeze":
- The cursor moved normally, but clicks did nothing;
- Ctrl+Alt+Del responded instantly, and coming back from it, everything returned to normal;
- Alt+Tab worked during the "freeze";
- The scroll wheel worked;
- Only the foreground program responded, everything else was dead, even when I brought it to the front with Alt+Tab;
- And the weirdest part: sometimes the auto-scroll cursor (the middle-click one) appeared without me clicking anything.
The pattern that fooled me 3 times.
This is the part I most want people to find, because it's what kept me chasing the wrong suspects for weeks. Almost every fix I tried appeared to work:
- Moved the mouse to a different USB port → quiet for days → relapse;
- Cleaned the keyboard and the Logitech G502 with isopropyl alcohol → quiet for days → relapse;
- Replaced the entire keyboard → quiet for ~3 days → relapse.
Everything that got ruled out (in order, so you can appreciate the size of this rabbit hole).
- Full clean install of Windows → problem persisted;
- RAM in Task Manager → low usage, all normal;
- Disk (CrystalDiskInfo) → clean SMART;
- CPU/GPU temps → fine;
- Windows Memory Diagnostic → no errors;
- Hung Explorer? → Restarting explorer.exe during a freeze changed nothing;
- Moved the mouse to another USB port → "fixed it" for a few days... then it came back;
- Replaced the ENTIRE mouse → "fixed it" for a moment... then it came back (or I thought so?!);
- Disabled USB selective suspend + removed ghost devices in Device Manager → nothing;
- Stuck modifier key? (phantom Ctrl/Alt/Shift) → cleaned the keyboard with isopropyl alcohol → "fixed it" for days... then it came back;
- Replaced the ENTIRE keyboard → "fixed it" for 3 days... then it came back;
- XMP → this one deserves its own chapter: I enabled the 5600 profile and got a blue screen. Turns out the i7-12700KF (12th gen) officially supports only DDR5-4800 on the memory controller. Disabled it, BSODs gone (but the "freezes" weren't);
- Gigabyte's DDR5 Auto Booster → it was on "Auto," silently overclocking my RAM to 5000 without my knowledge. Disabled it → nothing;
- Updated BIOS and chipset drivers → nothing;
- Fury CTRL (RAM RGB software) → uninstalled → nothing;
- Clean boot (msconfig) → problem CONTINUED even in a clean boot;
- Filter drivers in the input stack (reg query on the keyboard/mouse classes) → clean, only kbdclass and mouclass;
- Logitech G Hub → uninstalled → problem persisted.
Eighteen suspects. Eighteen acquittals.
The turning point.
Three clues closed the net:
Clue 1: during one "freeze," the browser accepted clicks but the Start menu didn't. Later, the reverse. Meaning: the system was NEVER frozen, something was stealing the clicks.
Clue 2: Alt+Tab brought another window to the front, but it stayed dead to clicks. That's the signature of stuck mouse capture: when a window captures the mouse, ALL clicks go to it, no matter what's in front. Keyboard focus and mouse capture are independent things in Windows. And the Ctrl+Alt+Del secure desktop forcibly cancels the capture — which is why it "unfroze" everything.
Clue 3: the auto-scroll cursor showing up on its own. Auto-scroll is triggered by the middle click (clicking the wheel). If it appears with nobody clicking... the system is receiving middle clicks nobody sent.
Caught red-handed.
I opened an online mouse tester site and left it running. Result: MIDDLE CLICKS counting up on their own, with my hands off the mouse. Spinning the wheel 700 times registered 4 phantom clicks the switch fires from vibration, I guess.
The complete mechanism of the "freeze," explained:
- The worn middle-click switch fires a phantom click;
- The foreground window enters auto-scroll mode and captures the mouse;
- Every other window goes dead to clicks (even via Alt+Tab), scrolling still works (pan mode), the cursor moves normally;
- Ctrl+Alt+Del → secure desktop cancels the capture → "everything goes back to normal."
Every bizarre symptom, explained by ONE ten-millimeter component.
Bonus: the button also had a double failure: it fired on its own, but didn't register when I clicked it on purpose (likely a cold solder joint or degraded internal contact: vibration closes the circuit, pressure opens it).
The fix
Reinstalled G Hub for 10 minutes just for this: enabled the G502's onboard memory and assigned "Disable" to the middle button. It's stored in the mouse's own chip: works with no software running at all. The switch can fire all it wants: the mouse no longer transmits anything from that button. Then I uninstalled G Hub again.
Open-link-in-new-tab can be remapped to a side button, or just use Ctrl+left click.
Lessons (for anyone hunting a similar ghost)
- If Ctrl+Alt+Del responds instantly, your PC is NOT frozen. Locked-up hardware doesn't open the secure desktop. The problem is software/input in your session;
- If the cursor moves but clicks are dead, suspect stuck mouse capture: a phantom button (from the mouse OR another HID device) or a stuck modifier key;
- Auto-scroll cursor appearing on its own = phantom middle click. Go straight to a mouse tester;
- With an intermittent problem, "it stopped after I did X" proves nothing. Only "it came back despite X" proves anything. Set a trial period (I used 7 days) before declaring victory;
- An online mouse tester is the most underrated diagnostic tool there is: leave it running in the background and it catches the phantom event with a timestamp;
If you're going through something similar: test Alt+Tab during the "freeze," check whether scrolling still works, and leave a mouse tester open. It might save you the weeks I lost.