Just stops, doesn’t do anything, just the mouse arrow moves.
An important thing:
The crashes start only after an update.
Do you mean it becomes unresponsive, or programs close by themselves? Does it freeze on whatever screen is up at the time? You say you still have the mouse. Can you right-click the bottom task bar when this happens and open task manager: find out what process is using most of the CPU?
If the above isn’t accurate, describe more accurately what it’s doing.
It becomes unresponsive! The programs don’t close, totally freeze, mouse moves, but can’t click.
The exact problems are:
When i start the computer it starts normally, but after I trying to open something from or copy to the 300 GB hard drive (simply click on its icon from the “My computer”, the computer immediately crashes (unresponding). Also when i want to open the Recycle bin, this happens (maybe the recycle bin opens the 300 GB hard drive too). And sometimes crashes suddenly.
BUT when I turn off one of the parmanent protections, and try to use the 300 GB hard drive, and re-enable protection, it works correctly until the next computer restart.
The another problem is that when avast found a threat on the flash drive, the browsers (IE and Firefox) become very slow until the next computer restart, even the flash drive was removed.
It is an external hard disk 
Can’t handle external hard drives?
At school when I put my pen drive to the pc (ram half 512mb and OS windows Xp SP2)
Well sometimes it can open properly and sometimes it freezes when “my computer” is opened
When I close “my computer”, crash…everything is gone on the screen except wallpaper and cursor.
What I do is that I remove the pen drive (Without doing safely remove might lose data) and the screen returns to normal again…
The pendrive works fine until Avast doesn’t find a threat. The computer doesn’t crash because of the pendrive, just slows down the browsers.
Actually I am wondering if your external hard disk is not overloaded…or that your computer is not reading it too slowly
No the hard disk isn’t slow without Avast, but when Avast is turned on (after the permanent protection switched off and after switched on), writing to the hard drive is slow (halting). The HDD isn’t overloaded (245 GB free)
So the 300G hard drive is an external hard drive, then.
I recommend you try the MBAM program linked to in reply 18, first on your own computer. Run a quick scan. Have it remove anything found.
If anything was found, run a second, full scan. Remove anything found.
Reboot immediately if prompted.
Then, plug the external drive in and scan that.
Avast can’t removes malwares?
Mostly, Avast can, when it is detected.
MBAM is more aimed at trojans and rogues, and has a very good reputation as a demand (or resident) second scanner.
Try it.
Update it after installation. Updates are typically ~5Megs.
Ok, I’ve installed, updated and run.
It found 16 Trojans! Trojan.Agent
15 exe files (in C:\Windows\Temp) and 1 registry key
But the computer still crashes because of Avast!
Post the Mbam log.
It’s hungarian.
Translation to english:
Malwarebytes Anti-Malware 1.50.1.1100
www.malwarebytes.org
Database version: 6439
Windows 5.1.2600 Service packet 3
Internet Explorer 7.0.5730.11
The 2011.04.25. 17:30:55
mbam-log-2011-04-25 (17-30-55).txt
The type of an examination: Full examination (A:|C:|F:|)
Examined objects: 240431
Time passed: 5 clocks, 16 minutes, 16 seconds
Infected memory processes: 0
Infected memory modules: 0
Infected system descriptor keys: 1
Infected system descriptor values: 0
Infected system descriptor data elements: 0
Infected portfolios: 0
Infected files: 15
Infected memory processes:
(Cannot be found malicious elements)
Infected memory modules:
(Cannot be found malicious elements)
Infected system descriptor keys:
HKEY_CURRENT_USER\SOFTWARE\Microsoft\Windows\CurrentVersion\Ext\Stats{00000005-0000-0000-0000-100009000004} (Trojan.agent) → Quarantined and deleted successfully.
Infected system descriptor values:
(Cannot be found malicious elements)
Infected system descriptor data elements:
(Cannot be found malicious elements)
Infected portfolios:
(Cannot be found malicious elements)
Infected files:
c:\WINDOWS\Temp\win14a7.tmp.exe (Trojan.Agent) → Quarantined and deleted successfully.
c:\WINDOWS\Temp\win14c2.tmp.exe (Trojan.Agent) → Quarantined and deleted successfully.
c:\WINDOWS\Temp\win1aa.tmp.exe (Trojan.Agent) → Quarantined and deleted successfully.
c:\WINDOWS\Temp\win68c.tmp.exe (Trojan.Agent) → Quarantined and deleted successfully.
c:\WINDOWS\Temp\win6e5.tmp.exe (Trojan.Agent) → Quarantined and deleted successfully.
c:\WINDOWS\Temp\win733.tmp.exe (Trojan.Agent) → Quarantined and deleted successfully.
c:\WINDOWS\Temp\wina34.tmp.exe (Trojan.Agent) → Quarantined and deleted successfully.
c:\WINDOWS\Temp\wina4b.tmp.exe (Trojan.Agent) → Quarantined and deleted successfully.
c:\WINDOWS\Temp\winad8.tmp.exe (Trojan.Agent) → Quarantined and deleted successfully.
c:\WINDOWS\Temp\winaed.tmp.exe (Trojan.Agent) → Quarantined and deleted successfully.
c:\WINDOWS\Temp\winc2d.tmp.exe (Trojan.Agent) → Quarantined and deleted successfully.
c:\WINDOWS\Temp\winc40.tmp.exe (Trojan.Agent) → Quarantined and deleted successfully.
c:\WINDOWS\Temp\wincc1.tmp.exe (Trojan.Agent) → Quarantined and deleted successfully.
c:\WINDOWS\Temp\winccb.tmp.exe (Trojan.Agent) → Quarantined and deleted successfully.
c:\WINDOWS\Temp\wind50.tmp.exe (Trojan.Agent) → Quarantined and deleted successfully.
- Run a boot time scan with avast.
- Run Mbam again.
If your system is clean follow step 3-6 - Run CCleaner. http://www.piriform.com/ccleaner
- Update your IE to version 8.
- Run MS update.
- Report back.
I don’t use IE!
Your system does anyway. 