what latest OS i can upgrade my Mac Book Pro 4 1 to ?

According to sources such as MacTracker and other, your computer model should be

able to run the latest OS X (Yosemite) given enough additional resources to do so...

Although that may be possible, given the vintage, it may not be the best one to try first

and you'd have to upgrade (Buy Snow Leopard 10.6.3 retail DVD from Apple online) to

then be able to update that system, which then would allow you to look into App Store

online to get a newer OS X system. The DVD is about $20. and the Combo update from

the Software Updates once that is installed (Combo 10.6.8 v1.1) is free.

retail DVD install OS X 10.6 Snow Leopard:

http://www.apple.com/shop/product/MC573Z/A/mac-os-x-106-snow-leopard

link to download update combo to the above OS X once it's installed

• Mac OS X 10.6.8 Update Combo v1.1

However, that said, the computer could need more RAM memory chips installed to run

better; and also depending on the age and capacity of the internal hard disk drive, it

may need to be upgraded or replaced with a larger capacity and perhaps faster RPM

rotational drive (7200-RPM) -- or maybe a Solid-State-Drive that has no moving parts.

There are two MacBook Pro models which use the 4.1 identifier. A 15-inch + 17-inch.

For purposes of upgrading RAM memory capacity, and some other items such as a

later OS X version upgrade, they are the same. Some internal components may be

different, so that aspect is a matter of correctly identifying the computer at time of a

hardware upgrade to later spec storage drive or other parts, where they may vary.

Maximum Memory 6.0 GB (Actual) -- 4.0 GB (Apple)

Memory Slots 2 - 200-pin PC2-5300 (667MHz) DDR2 SO-DIMM

• MacBook Pro: How to remove or install memory - Apple Support

Since several models of MacBook Pro are included in this page be sure to note the

exact build model and specs of yours so as to not be confused about the numbers.

And again, according to http://mactracker.ca downloadable database application...

IF yours is the MacBook Pro (15-inch Early 2008) model, these specs hold:

OVERVIEW

Introduced February 2008

Discontinued October 2008

Model Identifier MacBookPro4,1

Model Number A1260

EMC 2198

Order Number MB133LL/A (2.4 GHz), MB134LL/A (2.5 GHz)

Initial Price $1,999 (2.4 GHz) $2,499 (2.5 GHz)

Support Status Vintage

Case Lightweight aluminum alloy

Weight and Dimensions 5.4 lbs., 1" H x 14.1" W x 9.6" D

PROCESSOR

Processor Intel Core 2 Duo (T8300, T9300, T9500) ("Penryn")

Processor Speed 2.4, 2.5, or 2.6 GHz

GRAPHICS

Graphics Card NVIDIA GeForce 8600M GT

Graphics Memory 256 MB (2.4 GHz) or 512 MB (2.5/2.6 GHz) GDDR3

Display Connection 1 - Dual-link DVI (VGA, Composite and S-video with adapter)

Display Modes Dual display extended and video mirroring

External Resolution Up to 2560 by 1600 pixels

Camera Built-in iSight

Hard Drive Interface 1.5 Gbps Serial ATA (SATA)

Optical Drive Interface Ultra ATA/100 (running at UATA/66)

Some compatible hard drive & SSD options exist at http://macsales.com (OWC)

that should be considered, as they also have some video how-to-install guides.

Another source of upgrade or part replacement info is iFixit.com repair guides.

https://www.ifixit.com/Device/MacBook_Pro

I'm looking at 2:30AM local time here, so I'm going offline now...

In any event...

Good luck & happy computing! 🙂