Currently Being ModeratedMar 2, 2013 9:06 AM (in response to MAHESINH)
First you need to upgrade to 10.6.8. The 10.6 Snow Leopard DVD is back in the Apple online store. You can get it for $19.99. You will need to be running 10.6.8 to access the App Store to order Lion or Mountain Lion. http://store.apple.com/us/product/MC573/mac-os-x-106-snow-leopard
First we need to know which one of the 9 different models of MacBook you have. To see which model you have go to the Apple in the upper left corner and select About This Mac, then click on More Info. When System Profiler comes up check the Model Identifier and post it back here.
The Early 2006 model 1,1 Core Duo can only run a maximum of 10.6 Snow Leopard.
The models Late 2006 Core 2 Duos 2,1 through Early 2008 4,1 can only run a maximum of 10.7 Lion.
The Late 2008 model 5,1 Aluminum Unibody through the Mid 2010 White Unibody model 7,1 can run 10.8 Mountain Lion.
Currently Being ModeratedMar 2, 2013 9:10 AM (in response to MAHESINH)
For a non-technical answer (frederick1943 handled the technical just fine) ...
Many find that running SL on older system is the best solution, as Lion or better has more "overhead" than SL. They also think that Lion has many "modifications" to the interface that make them sad, such as "Save As" not being a direct option in Apple-provided programs and needing to juggle "versions" of a file.
But your mileage may vary if you decide to go to Lion or ML.
Currently Being ModeratedMar 2, 2013 10:12 AM (in response to MAHESINH)
If you are using any PPC applications then stick with 10.6.8 as Rosetta is not available with 10.7 and above.