How do I block access to porn sites from my PC?

A good discussion in protecting your family from porn.

http://forums.cnet.com/7723-6620_102-559111/how-do-i-block-access-to-porn-sites-from-my-pc/?tag=nl.e497

How to clean Backdoor Trojan Virus

The Story :

My colleague found a thumb drive on the street. He plugged it into his PC and yeah.. you got virus. The thumb drive is full of viruses that infected exe and flash files. Many programs no longer work.

How I check:

1. I disable the system restore in the PC
2. Take the hard disk out and plug it into my test PC with Windows 7 and Symantec Antivirus.
3. I use Symantec Antivirus (Symantec Endpoint Protection 12.0) to scan the hard disk.

What I found :

• Antivirus managed to find and clean 6 viruses (picture above)

How to fix it :

1. Take out the cleaned hard disk and put back into the PC
2. Re-install all the corrupted application.
3. Install Symantec Antivirus into the PC.

Additional notes:

• Most virus can't be clean within Windows of the infected PC. It is best to take out the hard disk and clean it from other PC.
• You must disable the System Restore before cleaning viruses. 

More information about Symantec Endpoint Protection and Norton Antivirus.

Cleaning PC interior from dust

The story:
10am in the morning. A PC was returned from construction site due to virus problem. The CPU interior was filled with layers of dust. Even the processor heat sink is somewhat clogged.

Here how we clean it :

1. Prepare a small brush and a vacuum cleaner
2. Turn off the PC.
3. Open the casing to expose your PC's gut, start the vacuum cleaner
4. Use the brush softly brushing off dust on the motherboard, CPU fan and others with the vacuum nozzle pointed at the brush to suck up dust
5. Do this until you clean the whole interior. Do not wet the brush.
6. Clean the clogged heat sink by removing the fan from the top of the heat sink (CPU fan are normally attached to the heat sink by hooks or clicks. Use the brush to brush between the pillars of the heat sink.

(Refer picture below)

Additional notes :

• always use small brush as it can go in small gaps
• if you don't have a vacuum cleaner, do the cleaning outside your home/office as you will poison everyone else with dust otherwise.
• never turn on the PC during cleaning

How to fix 'Windows could not start because the following file is missing'

The story :
Just as I walked into office, sat down and had a sip of water, my phone rang. That's usually bad news on a Monday morning. 


2nd floor purchasing officer called. Her PC can't start, need to press 'r'. Yes, that's Windows files corrupted. That's what happend when system can't find the right files to start Windows. The tale tale sign of hard disk problems. (picture below)

How I check :

1. Don't bother to press 'r', you need the windows CD and use Dos command to check (hey, where's my 2 inch thick Ms Dos 6 book?).
2. Just take the hard disk out and connect it to my test PC running Windows 7 (another PC). 
3. Backup all documents in desktop and my document (normally files type doc, xls and pst need to backup) into my network storage drive.
4. Use Checkdisk and DiskScan 3.3 to confirm if the hard disk is defective.
5. You may use Hiren Boot CD to diagnose the hard disk problem without taking out the hard disk. Just download the CD image, Burn it into a Bootable CD. Use the CD to boot your PC and run HDDScan 3.3.

What I found:

Checkdisk and DiskScan confirm bad block and damaged files system. (picture below)

How I fixed it :

1. Change a new hard disk and re-install Windows and all applications.
2. Restore files from network drive.

Additional notes :

• You may try cloning the damage hard disk (with Acronis TrueImage or DiskClone)  to a new one only if checkdisk (Scan & recover bad sectors) can fix the drive. This will save you time on re-installing Windows.
• But that depends on luck and the amount of bad blocks. For drive with minor bad blocks, it may work. But for badly damaged drive, better start from scratch then 10 step back.

How to fix Windows restart due to motherboard failure

The story :

This PC was returned from our construction site. The problem was that it is unstable. It shut down or reboot itself.


Specification :
- Pentium Dual Core
- Gigabyte G41 Combo Mainboard
- 2 GB RAM
- 500GB Hard  disk


How I check :

1. I tried testing with PC diagnostic tools (PC Doctor or BurnIn Test) but doesn't find any problem. 
2. I checked  Bios (press 'Del' when switch on power) and check the processor temperature. It is OK. 36 Celsius. (OK between 30 to 50 degree Celsius)
3. Check motherboard physically to see of the are any defective capacitor (leaking capacitor)

What I found :
Found leaking capacitor (see picture)

How I fix it :

1. Replace the motherboard with a new one.
2. Unless you're a trained technician, I don't recommend you changing the leaking capacitor yourself.

Additional note :

• There may be other component that may cause PC to reboot. Defective RAM and graphic card can be diagnosed with software testing tools such as PC Doctor or Passmark BurnIn Test.
• Replacing capacitor is dangerous as capacitor keep electrical charge even though the PC is turned off. Don't do it unless you're a professional.

Hot to clean dirty print Job (HP Laserjet P1102)

The Story:

Our QS Vincent complaint print out dirty with patches and vertical lines. This is not an old printer, maybe 1 year old. I doubt it's the printing mechanism problem.

Specification:
HP Laserjet P1102


How I check :

1. Take out toner and check for leaks inside toner compartment
2. Clean printer interior (toner slot) with brush
3. Check & clean toner OPC drum (the green drum) with tissue
4. Put toner back in & test print

What I found :
Found a piece of paper stuck on the toner OPC drum

How I fixed it :

1. Remove the paper (clot), clean the OPC drum with tissue.
2. Clean any spill in the printer with small brush.
3. Print a few pages to clean out the existing spills on the roller.

Additional notes:

• always turn off the power when cleaning
• most of the time, it is the toner problem rather then printer itself.
• if toner OPC drum keeps get clogged with toner, change new toner.
• sometime lines are due to damaged fusion heater film. You may see pieces of film inside the toner compartment. That, you need a pro to repair.

How to diagnose Windows 7 desktop freeze due to hard disk failure

The story :
Our sales department Ginny told me her PC consistently hang. Upon restart, Windows run check

disk and report repairing files. Once boot in Windows desktop, it hang again. I  had removed some software such as third party CPU speed booster and antivirus software that might caused it to hang, but it happened the next day. 

Specification :

- Asus P5P43TD Board

- Intel Core 2 Duo E7500 Processor

- 4 GB RAM (2+2)

- Western Digital 1.0TB Hard disk WD10EARS

- Win 7 Home Premium 32 Bit

Additional information :

- Windows 7 Desktop Freeze (Mouse can move but in circle& can't click anything)

How I check :

1. Boot into safe mode and check event log for errors
2. Found the following error "\Device\Harddisk0\DR0, has a bad block" (picture below)
3. Take hard disk out and connect it to another PC. Run disk diagnostic tool such as
   check disk and HDDscan 3.3

What I found :

Disk check result confirm defective hard disk that caused Windows desktop to freeze (due to unable to read files) (picture below)

 

How I fix the problem :

1. backup hard disk files in user profile (c:\users) into external hard disk (check other
   partition or folders for files to backup) 
2. change a new hard disk and re-install Windows
3. restore files from external hard disk

Additional note:

• If Windows can boot to safe mode, make sure check (system) event log in control panel - administration - Event log and check for problems (!).
• Backup files to external drive before running hard disk test
• Disk utilities as disk test may further damage the hard disk and cause permanent data lost
• Despite disk utilities can repair the defective hard disk, I don't recommend to continue using the hard disk due to it may fail again soon.