Upgrade from Mountain Lion

No, as long as both are on the same account.

No need for a clean install, especially on a first time upgrade. OS X isn't "sloppy" like Windows (or have a Registry) and there is very little benefit other than eliminating "junk" you installed.

You only purchase once the software that you purchase on the Mac App Store. This includes OS X upgrades. A clean install of OS X is an extraordinary remedy for an intractable problem. It is not a recommended standard upgrade procedure. Doing so makes about a much sense as amputating your foot because your toe itches. To the contrary, Apple adopted the Mac App Store for OS upgrade distribution in part to encourage simple upgrades.

simps100 said:

Firstly i have a iMac and MacBook Pro, will i need to purchase the update twice for both or will i just need to buy it the once?

Secondly on Windows it was always recommended to do a clean install, is this the case for OS X also? If so is it as easy to do as windows?

Click to expand...

You can download the installer as many times as you like (or download it once and copy it). The purchase is tied to your Apple ID, of course.

No. Default installation replaces the SYSTEM, but leaves your apps, user data and settings all intact. I've installed OS X versions 10.3 to 10.8 in the place of pre-existing systems with no problems (and migrated my user account across 4 Macs!).
In Windows, it seems that the default remedy for any problem is to reinstall the system. In OS X, there is usually very little need to ever reinstall the OS. Your problems are likely to be elsewhere (user account, settings, incompatible third-party apps, drivers, etc).

Hi
Im also on my first iMac ever and it has ML 10.8 now..
So if I update the system to Mavericks later..
What will be the risk for all my software / apps that I have bought and installed??
Does that stuff normally just keep on working or do I need to await that each one support mavericks??
My most important ones being:
VM Ware Fusion
Amplitube Fender
Amplitube
Paragon NTFS

Also how do I do the upgrade to mavericks?? any special procedure to this kind of thing??
And yes on windows theres quite a big deal to upgrade the OS..and always total reinstall more or less...so used to this being a hardship.

Also do you guys think that one should upgrade at all??
Im not so sure I like the looks of Mavericks with the new bar and all...
best regards micael