If the iPad is administered by your company, you can not remove this restriction without completely restoring the iPad. At which point it will probably not be able to access the company websites or use any company apps. And you'll probably piss off the IT department.
This is the price of getting a free iPad from you company, or having the privilege of using you own iPad on the company network.
If it's not a company iPad, then follow Tim's advice. The restrictions settings are found under Settings > General > Restrictions. You'll need the four digit code that was used to set restrictions to unset them. Talk to the person who restricted it.