Not able to Insatll TestNg

Hi,

I am trying to install TestNg on my client's Virtual Machine(VM) but getting below error message.

[b:2s4avlkh]Unable to read repository at http://beust.com/eclipse/content.xml.
peer not authenticated[/b:2s4avlkh]

I don't have Admin privilege.
I tried with New Software Installation and Eclispe Market Place.

[b:2s4avlkh]Note[/b:2s4avlkh]: As I get random VM each day , I used to Install TestNg everyday morning and it worked fine . But from previous week not able to install.
Please help me on this .

Thanks,
kannan C