Weird wireless connectivity loss

[vibhor_agarwalin]

First of all what's OP 
Looks like it's me but what's the full form 

Didn't think network card is a problem as laptop works perfectly fine with my neighbors wifi network which is much farther & weaker than mine.
Believe that means card is good?

[Geek-9pm]

First of all what's OP 
Looks like it's me but what's the full form 

Didn't think network card is a problem as laptop works perfectly fine with my neighbors wifi network which is much farther & weaker than mine.
Believe that means card is good?

Yes, OP is you. Original Poster.
There are a number of ways to do diagnostics. The members here can offer you a set of steps to take to find a solution. But you can not just pick and choose what steps your think  are relevant, unless you really do have more experience and background in networking.
Anyway, did replacing the router solve the problems?
If so, I am glad you  get it fixed. 

EDIT: From the archives.
Troubleshooting wireless netwooks
Netwook

[vibhor_agarwalin]

Phone worked fine.
Didn't have the opportunity to work on the culprit laptop.

Will get back soon.

[vibhor_agarwalin]

Worked fine for a couple of days.

If this continues to work, then mystery still remains what's wrong with that router?
Only effects one laptop & a mobile. Everything else works perfect.