MacBook 4,1 - optimum OS X version?

stay at 10.6. 2gb is the minimum ram requirements for 10.7

I concur with shldr2thewheel, you loose a lot of backward compatibility when jumping to 10.7 and don't really get much in terms of new features or performance increases. I miss 10.6....

Once you are at 10.6.8 Lion is still available from Apple. You will have to call Apple Customer Care 1-800-692-7753 or 1-800-676-2775. to purchase it. Then within 3 days you will get an email with a code which you can use to download Lion from the App Store. The price is $19.99.

Lion will require at least 2gb of RAM but really needs 4gb to run smoothly. The model 4,1 (Early 2008) can use 6gb of 200 pin 667mhz PC2-5300 RAM

As for third party programs see this list for compatibility with 10.7 http://roaringapps.com/apps:table

Also Lion doesn't run any Power PC programs. To see if you have any Power PC programs go to the Apple in the upper left corner and select About This Mac, then click on More Info. When System Profiler comes up select Applications under Software. Then look under Kind to see if any of your applications are listed as Power PC. Universal and Intel will run under Lion.

Before Mac switched to Intel processors in 2006 they used Power PC processors from 1994 to 2005. Power PC 601 through 604, G3, G4 and G5. Applications written for the Power PC processors need the application called Rosetta to run on Intel processors. This was part of the Operating System in 10.4 and 10.5 but was an optional install in 10.6. With 10.7 Lion Apple dropped all support for Power PC applications.

These are good online stores for Mac compatible RAM

OWC http://eshop.macsales.com/shop/memory/MacBook/DDR2/ - They offer Mac tested RAM at very good prices.

Crucial Memory http://www.crucial.com/ - good place to buy RAM from all over the world. They also have an excellent memory selector that allows you to choose memory based on your computer's model

Data Memory Systems http://www.datamemorysystems.com/apple-memory.asp - another good, cheap place to buying RAM if you live in the U.S.

Here are instructions on replacing RAM in a MacBook with a removable battery. http://homeoffice.consumerelectronicsnet.com/articles/viewarticle.jsp?id=44404

If you don’t have the tools to open up the MacBook OWC has a set for $5.
http://eshop.macsales.com/item/OWC/TOOLKITMHD/

My macbook pro didn't show new software update my current software update is mac osx 10.5.8. So how can i update it to 10.6.8

and my itunes is not working it show an error "Tunes requires QuickTime 7.5.5 or later. For more information on upgrading your computer, visit http://www.apple.com/quicktime" how i solve this.

My macbook pro didn't show new software update my current software update is mac osx 10.5.8. So how can i update it to 10.6.8

and my itunes is not working it show an error "iTunes requires QuickTime 7.5.5 or later. For more information on upgrading your computer, visit http://www.apple.com/quicktime" how i solve this.

Hardware Overview:

Model Name: MacBook Pro

Model Identifier: MacBookPro4,1

Processor Name: Intel Core 2 Duo

Processor Speed: 2.5 GHz

Number Of Processors: 1

Total Number Of Cores: 2

L2 Cache: 6 MB

Memory: 4 GB

Bus Speed: 800 MHz

Boot ROM Version: MBP41.00C1.B03

SMC Version (system): 1.27f3

Serial Number (system): W8831062YK0

Hardware UUID: 4F9B7886-1C57-5A3D-A41A-74357C28539A

Sudden Motion Sensor:

State: Enabled

I'm switching back to 10.6 myself. Lion was a fustercluck on my 4,1 from the get go. Too heavy on the back end with RAM for what had always been a reliable OS; it made the laptop more or less productive as a DVD player than a computer.