I have old laptop and I decided to install linux for learning networking in linux.
My laptop is Samsung R60y. First I was installed Ubuntu and I install samba server VPN and web server, every thing working fine, but the problem is that, I am getting crashes. After getting crashing I Thought that problem is in Software in kernel, And i decide to use debian 9 and clean install OS. However with debian still getting those crashes. I take a photo of trace when server crashes:
1. ScreenShot
2. ScreenShot
I get this crash various times. Sometimes after 1 minutes from laptop on, sometime after 1 hour from computer starts, and sometimes just after few days.

It looks kernel related. But you've cleared the kernel. If it wasn't a new install I'd be thinking malware. But that's 10 years old. Pc what's the spec?
Try booting with the 'noapic' option. Post the output of lspci, and free

EDIT: What we need to see is the start of the error message, not the last ones, which are part of the tail spin. Try shift+ page up in the console when it happens and take a screenshot.

My laptop specifications:

• Core 2 Duo T5450 1.66 GHz
• 2.5 GB ram
• 120 HDD
• Graphics: ATI Radeon X1250 128MB

I will post start of error message when it crash again. And 1 question how to boot with noapic option ? And how to get output of lspci and free, because I am new on linux.

I have an old AMD based laptop with the X1250. Mine has a twin turion and AMD North bridge/Southbridge.

The graphics is a POS. AMD are embarrassed they charged money for them. Your ram and HDD are underspecified, and you will have continual issues. The LAST thing you want to do is to set up a situation where you are swapping out or running on low resources. Phones and tablets come with more ram these days. My tablet has 2G and my phone 4G.

My advice would be not to use KDE or gnome, use console mode unless you need/want X, and keep the traffic on any servers low. That box is definitely not server material. What desktop are you running? What distro?

There's some setting for the default log level. You can override it on the kernel boot line. A log level of 7 is debug (usually too much) but 5 or 6 might tell you more and log it. This may do it running.

If you installed amd64, try it with i386.

I am already using only console, no graphical interface
I am installed i386, I know that is stands for x86 or 32 bits OS.

Re read post #2 and let's have some information.

I think that was a hardware, because this pc is over 12 years old, I try install windows xp even with windows I get BSOD sometimes. I bought new laptop for this and now don't get any crashes.

It's easy to think that. XP included a BSOD, which m$ took several versions to overcome.

You have actually proved nothing. That's equivalent to diagnosing an engine failure for a non starting car. It may be ignition, coil, fuel, carb,plugs, or engine failure.