How I fixed a freezing Windows 7 laptop
HUGE DISCLAIMER: for all things you're trying because of this blog post, please be aware that I do not take any warranty whatsoever. Because fixing my computer is not my business.
Despite the disclaimer, here's the story how I got a arbitrarily freezing, completely unusable Window 7 laptop working again.
Please note that I write this article mostly for selfish reasons – just in case I'm pleased to fix something similar in the future. So don't expect a nicely written article with no spelling mistakes etc.
But still, it might be helpful for you if you sit in front of a frozen Windows PC yourself at the moment.
Got approached by my neighbor with a 5 year old Samsung laptop with a conventional harddisk built in. Strange thing was that the laptop started reasonably fast and I was able to pass login. However, after a few minutes the PC froze entirly.
- The screen was left as is, so no blue screen
- No response to anything I did with the mouse or the keyboard
- Only way to bring the system down was a hard shutdown with on/off button
- Running the system in Windows protected mode worked just fine
- According to the LED, harddisk was busy all the time
- Heck I wasn't even able to launch Task Manager or Resource Monitor
- Waiting for 15 to 30 minutes brought back the PC for a short period. Got frozen after that again.
I figured that it might not be a software problem. Seemed that there was something wrong with reading and writing from the harddisk.
First thought: I needed to get Resource Monitor launched.
The Things I Tried
Here's what I tried in mostly chronological order.
Uninstalling Norton 360
- Sometimes I managed to launch Task Manager and saw that Norton's n360.exe was on top of the list most of the time.
- Uninstalled it by launching in protected mode
- After launching in normal mode, things were getting a bit better
Was is it a software problem against my initial suspicion?
Running AdwCleaner and Malwareytes
- Laptop was also used by kids. So a lots of "free" games, YouTube downloaders and stuff.
- Malwarebytes found about 1.500 threats. Here's a German instruction on how to use MalwareBytes.
- AdwCleaner reported about 250 problems.
The result: laptop was still freezing. Hardware problem?
Would running disk fragmentation solve issues?
- Checked if contents on disk was heavily fragmented. Nope.
Monitoring harddisk usage
- Back to my harddisk problem suspicion
- Due to less weight on the system through removing malware and Norton, I was able to launch Windows Resource Monitor
- Resource Monitor can be launched via Task Manager's performance tab.
- It allows to see which processes are accessing the harddisk and how the performance thereof is.
Strange harddisk behavior
- Response time of harddisk reads and writes was constantly extraordinary high in the ranges of 5.000 to 50.000 milliseconds
- Sometimes the disk utilization plot showed nothing for a while
- Compared to disk utilization metrics of my own laptop (also no SSD, d'oh!): response time was around 50 to 80 milliseconds while working
Running good old MS DOS chkdsk
- Started a Windows command prompt and ran chkdsk in various configurations
- No problem found
Booting laptop in Windows repair mode
- Hitting F8 while booting to bring up Windows boot menu
- Ran memory diagnosis from repair menu, no problem detected
Making a backup of user data
- In case I would have to reinstall Windows on C:
- I hate it when people store their data on the Windows partition
Running Samsung Recovery
- In my case had to hit F4 in the very beginnging of booting up to enter recovery
- No options there that would help me to diagnose hardware problems
Check if harddisk runs in PIO instead of DMA mode
- Explanation PIO vs. DMA
- DMA ... Direct Memory Access, no CPU power needed
- PIO ... Programmed Input/Output, involves the CPU and is considerably slower
- Wasn't able to quickly find information about that
- Wanted to check in Device Manager, but laptop was freezing all the time
- As far as I remember, wasn't able to spot this information in Windows protection mode too
Uninstalling Intel Rapid Storage Technology
- People on forums pointed out problems due to Intel Rapid Storage Technology
- Uninstalled it
- No improvements
Checking harddisk drivers in Device Manager
- Everything up to date
Searching for a tool to check the physical health of harddisks
- Stumbled upon this German YouTube video explaining harddisk diagnosis with Ultimate Boot CD
- With Ultimate Boot CD you're able to boot the PC from an USB drive or a CD and run various computer diagnosis tools
Running Samsung ES-Tool to check harddisk health
- Samsung ES-Tool comes with Ultimate Boot CD
- There we go: check reveals about 10 bad sectors shortly after starting the check
- Let the check finish. Took about one and a half hour (500 GB harddisk capacity by the way)
- Against my expectations, no more than those ten bad sectors were found
- Conclusion: backing up files earlier was a good thing.
- Concern: will I have to waste even more hours into solving my neighbor's computer problem?
Remembered that I read somewhere that Windows would be able to detect bad sectors and avoid writing stuff into it.
This Solution (In My Case)
- Looking how to do that with Windows. Here are instructions from Microsoft
- Open Windows Explorer
- Right-click the partition you want to check, e.g. C:, and select Properties
- In the dialog, choose Tools
- Click the Check now... button in Error-checking
- In Check disk options choose Automatically fix file system errors and Scan for and attempt recovery of bad sectors
- Hint: For the partion the OS is installed on (i.e. most of the times C:) you can only schedule the check to run at next startup
- Running check for partition D:. No problem detected.
- Running check for partition C:. Leaving the laptop alone, doing some programming stuff. Missing when check was finished, thus no clue what the check did.
- Using the laptop for a few minutes. Everything is fine. Considerably good performance when launching Word and browsing the web.
- See what Resource Manager has to say about harddisk utilization metrics.
- Wow, response time is in a normal range.
- Working with PC for a few more minutes. Computer seems to run fine!!
- Used the laptop for the next two days.
- Was never freezing again.
- Setup of CrashPlan to have a decent backup solution in place in case the harddisk will fail some day in the future.
Hope this article serves me well the next time I have to fix a freezing Windows PC.
Until then, hope it was helpful for you too.