I doubt if you can say that it is "my network". And once you're fired because of breaking into the company's network (that's a valid reason to be fired) you can't even say that it's your office.
Anyway, I'd start simple.Buy a laptop with Windows 7 (or and see if you can use that to access the Internet at work (either wired or wireless). If that doesn't work, it surely doesn't work at the company supplied hardware either.
Please help me to solve this issue. I am working in a big company. I have my office computer (windows xp) with internet. But I can't access the internet, because they are blocked by the administrator. I have a user account created by our company IT experts. I tried a lot of methods of hacking the admin password, but it didn't work. Now I decided to install an another OS in my computer (windows 7). Any problem to install this, after my installation can I boot both OS s? If any chance to catch this process by our admin. Please help me to solve this issue.