q+a After replacing the SIM card on my Nokia Lumia 638, Internet Explorer always shows a '403 forbidden error'.

Rashmi Ahmed

A setting on your phone must have got changed inadvertently. Try switching the browser from desktop mode to mobile mode or vice versa. Tap Internet Explorer; click on the three dots and on Settings. Change the website preference to either mobile or desktop and try browsing again. This usually solves the problem.

Board change

q+a If the motherboard of a phone is changed, will the IMEI number change too?

L. Dkhar

Different brands have different ways of handling this. If an authorised service centre of Samsung replaced the motherboard you would get back your old IMEI number because they have tools that backup and restore the EFS folder where the IMEI number is saved.

Motorola and Nokia will give you a new motherboard with a new IMEI number and also make sure that the old one is blocked. Apple does not replace the iPhone's logic board but changes the device (so a new IMEI number), making sure the old IMEI number is no longer usable. However, if you get the motherboard replaced by a corner shop you will not know whether the old IMEI number has been blocked..

Disk access

q+a The drive letter of my 500 GB Seagate external hard drive shows up on my laptop but does not open when I click on it. I have lots of memorable photos stored there. How can I access this disk?

Lipika Das

Right click on the drive and click on Properties. Open the Tools tab and click on Check Now. Make sure that 'Automatically fix files system errors' and 'Scan for and attempt recovery of sectors' are both ticked. Press Start.

If this does not solve the problem try each of these: connect the external drive on different USB ports on your laptop; plug it on to another computer; replace the cable. If the disk still does not work there may be a problem with either the disk or the adapter inside connecting from HDD to mini USB. You will be able to recover some of the data using the services of a professional disk recovery company but let me warn you that it will be very expensive.

Correct time

q+a Whenever I try to watch videos on YouTube, the webpage does not load and I get an 'invalid certificate' error.

Ajit Soren

If your computer's date and time is not correct, you will face this problem. Right click on the time and date at the bottom right of your computer screen and correct it. In many old computers, when the CMOS battery is dead, the BIOS settings are restored to defaults. The system date and time automatically reverts to a very old one, usually when the computer was manufactured. Replace the CMOS battery if the date and time is incorrect whenever you switch on your PC.

Factory reset

q+a Ever since I factory reset my Android phone, I keep getting notifications such as 'Google Talk Authentication Failed'. Also, I am unable to download apps from Google Play Store. It says 'Error retrieving information from server'.

Arjun Saha

Go to Settings-Applications--Manage applications and scroll down to Google Play and clear data and cache. Then scroll down to Google Services Framework and clear the data there too. Reboot your phone and you should be fine.

Send in your computer-related problems to askdoss@abpmail.com with bits&bytes as the subject line