You don't have to install, you can do it online and it will allow to fill all the fields and calculate the taxes.

It will ask you to pay only if you want to take printouts or want to submit online.

I haven't tried the downloadable version, but online definitely works.,

I need you help to understand my tax return ,

I have landed in 9th Dec 2007 and got job in 20th may 2008 . My wife joined me on 12 Jan 2008 . I am planning to fill my income tax return for year 2007 .
I have not generated any tax in year 2007 - till 19th may 2008 . My wife is still unemployed .

Please guide me to fill my tax return .