Hi Oshan,
The link I gave was for the same wireless card but different system model. Sometimes installing the previous versions of drivers might work.
Was it working without any issues in Windows 7? ( Prior installing Windows 8 ) If the card was working without any issues in Windows 7 then it should be an issue with Operating system/driver.
You can also try installing the previous version of the same wireless card from link: http://dell.to/WhBoyW and see if it exhibits the same behavior. Also make sure to install all the windows updates for the same if available and see if it works.
Another step you can try is to change the settings of wireless card to maximum performance from power options by following the steps below:
- Click 'Start' , type 'Power Options' in the Start Search box, and then click 'Power Options' in the 'Programs' list. If you are prompted for an administrator password or confirmation, type your password or click Continue.
- Click 'Change plan settings' under the power plan that is selected. For example, if the 'Balanced' option is selected, click 'Change plan settings' under 'Balanced'.
- Click 'Change advanced power settings'.
- In the 'Power Options' dialog box, expand 'Wireless Adapter Settings', and then expand 'Power Saving Mode'.
- In the list that appears next to 'On battery', click 'Maximum Performance', and then click 'OK' to save changes.
- Restart your computer.
Please share the findings.