How to pronounce 上 with the meaning of "when"?


I know how to pronounce and translate 上 in 1, but not sure if it is pronounced
うえ or じょう in 2 and if it is also translated "when". Could someone explain case
2 please?

>   1. 利用上{りようじょう}の注意{ちゅうい}  
>  caution when using
>   2. **computer name** 上で使用している **account name** の Firefox  
>  Firefox **account name** when using **computer name**
>




We pronounce it `じょう` like in Example 1 because we have `上` without any
particle between it and the previous word, and it simply means 'on'.

* * *

In Example 1, it kind of works if we call it `when`, but in general, [`上` is
used as a suffix](http://abacus.bates.edu/~kofuji/StudyResources/kanji.html)
to mean `as a matter of sth`. Its literal meaning is

> Cautions as a matter of usage

or even better, `precautions`. That's what happened in Example 1.

But you are confusing the order of words in Example 2. This 上 is _not_ the
suffix for `使用`, thus the translation `when using` or `as a matter of using`
is incorrect.  
It is right after the word **`computer name`**. That's a thing. It should mean
'on'.

Also, **`account name`** is a name of somebody, so that `の` works as a case
particle for indicating ownership.

> **computer name** 上{じょう}で使用{しよう}している **account name** の Firefox  
>  **Account name** 's Firefox running on **computer name**

* * *

Edit: I found out that this phrase can be interpreted 2 ways. The first one is
shown above. The other is:

> The Firefox running on **account name** on **computer name**

It's how we interpret the **account name** part. Firefox has a system that
allows multiple profiles to be made in one installation like chrome does, so
grouping `account name の Firefox` makes sense. But if you think of, for
example, a school, it is possible that `account name` means your school
account and that it can be used to log in to any computer in your school.
Thus, grouping `computer name 上で使用している account name` also makes sense.




We pronounce it `じょう` like in Example 1 because we have `上` without any
particle between it and the previous word, and it simply means 'on'.

* * *

In Example 1, it kind of works if we call it `when`, but in general, [`上` is
used as a suffix](http://abacus.bates.edu/~kofuji/StudyResources/kanji.html)
to mean `as a matter of sth`. Its literal meaning is

> Cautions as a matter of usage

or even better, `precautions`. That's what happened in Example 1.

But you are confusing the order of words in Example 2. This 上 is _not_ the
suffix for `使用`, thus the translation `when using` or `as a matter of using`
is incorrect.  
It is right after the word **`computer name`**. That's a thing. It should mean
'on'.

Also, **`account name`** is a name of somebody, so that `の` works as a case
particle for indicating ownership.

> **computer name** 上{じょう}で使用{しよう}している **account name** の Firefox  
>  **Account name** 's Firefox running on **computer name**

* * *

Edit: I found out that this phrase can be interpreted 2 ways. The first one is
shown above. The other is:

> The Firefox running on **account name** on **computer name**

It's how we interpret the **account name** part. Firefox has a system that
allows multiple profiles to be made in one installation like chrome does, so
grouping `account name の Firefox` makes sense. But if you think of, for
example, a school, it is possible that `account name` means your school
account and that it can be used to log in to any computer in your school.
Thus, grouping `computer name 上で使用している account name` also makes sense.

