Every MSP engineer has that moment.
The one where you confidently deploy something…
…and immediately regret your life choices.
This is mine.
😎 The Confidence Phase (A.K.A. “What Could Go Wrong?”)
It started with a simple idea:
👉 “Let’s clean up unused services across all client machines.”
Sounds harmless, right?
I wrote a PowerShell script that:
- Identified unnecessary services
- Stopped them
- Disabled them
Efficient. Clean. Beautiful.
Tested on my machine?
👉 Worked perfectly.
🖼️ The Vision vs Reality
Expectation:
Everything gets optimized. Client loves me. I get promoted. Maybe even a raise.
Reality:
Chaos. Absolute chaos.
🚀 Deployment Time
I pushed the script across multiple client machines.
Sat back.
Took a sip of coffee.
Waited for success messages.
Instead…
☎️ The Calls Start Coming In
- “Our system is acting weird.”
- “We can’t access some tools.”
- “Something just stopped working.”
And my personal favorite:
👉 “Did you guys change something today?”
At that moment, I knew.
👉 I messed up.
🖼️ My Emotional State
🔍 The Investigation
I quickly checked the script logs.
Everything looked… normal.
Which is never a good sign.
Then I dug deeper.
And found it.
💣 The Bug That Caused Everything
My script had a “simple” logic:
```powershell id="fail01"
if ($service.Status -eq "Running") {
Stop-Service $service.Name -Force
Set-Service $service.Name -StartupType Disabled
}
Looks fine, right?
Except for one tiny detail:
👉 I didn’t properly filter *which* services were “safe” to disable.
So the script happily disabled:
* Important system services
* Client-specific services
* Things that should NEVER be touched
Basically:
👉 If it was running… it was gone.
---
## 🤦 The Classic Mistake
I assumed:
> “If I don’t recognize it, it must not be important.”
The system disagreed.
Strongly.
---
## 🛠️ Emergency Fix Mode
Now I had to:
* Identify affected machines
* Re-enable critical services
* Apologize internally (a lot)
And most importantly:
👉 Fix the script properly
---
## 🧠 The Correct Approach (Lesson Learned)
This time, I slowed down.
---
### ✅ 1. Whitelist instead of blacklist
Instead of “disable unknown services”:
👉 I defined **safe-to-disable services only**
```powershell id="fix01"
$safeServices = @("ServiceA", "ServiceB")
foreach ($service in $safeServices) {
Stop-Service $service -Force
Set-Service $service -StartupType Disabled
}
✅ 2. Add confirmation logging
```powershell id="fix02"
Write-Output "Disabling service: $service"
Now I could track exactly what happened.
---
### ✅ 3. Add a “dry run” mode (GAME CHANGER)
```powershell id="fix03"
$dryRun = $true
if ($dryRun) {
Write-Output "Would disable: $service"
} else {
Stop-Service $service -Force
}
This saved me from future disasters.
✅ 4. Test like a paranoid engineer
- Different machines
- Different environments
- Worst-case scenarios
No more “it works on my machine.”
😂 What I Learned (The Hard Way)
1. PowerShell is powerful… and dangerous
One wrong script = big impact
2. Never trust “simple scripts”
Simple scripts cause complex problems
3. Always test at scale (safely)
One machine ≠ real environment
4. Dry run is your best friend
Seriously. Use it.
🧘 Final Thought
That day was painful.
But it made me better.
Now, before I deploy anything, I ask:
👉 “What’s the worst thing this script could do?”
Because trust me…
👉 It will find a way to do it.
👇 Your turn
- Ever broken something in production?
- Ever deployed a script you instantly regretted?
Let’s share the pain 😅