Application to check website availability around the world

Hello everyone,
I am on Windows XP, and looking for an application that could be used to check my website availability from cities / countries around the world.

Many times it happens that for some reason my website is unavailable from some cities of India, or Russia, or for example isn’t available via some internet providers in my own country.

So i thought there could be some sort of professional program like that, that could be flexible used to verify website availability from different cities / countries / internet services providers.

Any good suggestions around?

Big thank you in advance.

You could try something like pingdom, there are a few services that will test your site from multiple distinct locations around the world, but maybe not to the depth that you require.

Thank you for suggestion.

What i want its something like these online services:
Uptrends - Check website uptime, downtime, performance and availability.
Monitor Website Uptime and Availability Worldwide - Site24x7 Tool

Only that i want a bit more sophisticated application that could be installed on my machine, instead of an online service subscription.