If you can actually ACCESS Netflix on your Blu Ray player AND your computer, then your router/wireless connection is actually working fine.
That's half the battle right there.
Now you stated -- It happened suddenly giving me a message, " we are having trouble linking on to this title, please try another one or try again later"
So that tells me your Blu Ray and/or computer isn't having issues with your router.
When you cannot connect to Netflix with 50% of all your devices, it usually means you have to either set the Video Resolution back one setting so your device can download it, or you need to Deactivate and Reactivate your Device(s) to re-establish brand new connections between Netflix and the Device(s) that are not functioning correctly.
I'll show you a picture of Netflix's account page. You should find both the Change video resolution, and the Deactivate/Reactivate device(s) on it.
Now, you see the MANAGE VIDEO QUALITY setting Above that arrow? Select that first, set it back one lower video quality setting and see if you can get the computer/blu ray player to actually play what you want it to.
Remember....if you can connect to Netflix, then half the battle is won, and all you have to do is to get your Video quality reduced to see if it starts streaming again or not.
IF IT DOES NOT.....
Then access your computer and your account and Deactivate, then Reactivate your Netflix Devices.
I just did that for another customer, using my Netflix account and it really isn't hard to reactivate the device. I pressed the Netflix button on my DVD and it asked basic questions, and delivered the Activation code. I took that code to my computer and typed it in, and was done in 2 minutes.
As for the computer you have...if it WAS connected before, then it still is connected to Netflix.
If it was NEVER connected, then we have to set up your computer's wireless connection point to access the router FIRST. That's simply selecting a wireless connection on the computer, then selecting your router, then typing the router's password XXXXX just like you did with your Blu Ray player.
My only concern is that you have XP on your laptop. That may be challenging because it's two operating systems behind.