Если курсор не двигается, попробуй перезапустить устройство.

Если means if and introduces a condition.

So the structure is:

• Если
  • condition,
• then the result/action.

In this sentence:

• Если курсор не двигается = If the cursor isn’t moving
• попробуй перезапустить устройство = try restarting the device

This is very similar to English conditional word order.

Курсор is in the nominative case because it is the subject of the verb двигается.

Here:

• курсор = the cursor
• двигается = moves / is moving

Since the cursor is the thing doing the action, Russian uses the nominative.

The verb here is двигаться, which means to move (intransitive, or literally to move oneself).

So:

• двигать = to move something
• двигаться = to move

Because the meaning is the cursor isn’t moving, Russian uses двигаться:

• курсор не двигается = the cursor is not moving

The ending -ся is important here. It often marks a reflexive/intransitive form.

Двигается is:

• 3rd person singular
• present tense
• from двигаться

It agrees with курсор, which is singular.

So:

• я двигаюсь = I move
• ты двигаешься = you move
• он / курсор двигается = he / the cursor moves

In Russian, present tense can also translate naturally as English is moving, depending on context.

Russian normally uses a comma to separate the если clause from the main clause.

So:

• Если курсор не двигается, попробуй перезапустить устройство.

This is standard punctuation for a conditional sentence:

• If X, do Y.

Even when English might sometimes feel lighter with punctuation, Russian usually keeps this comma.

Попробуй is the informal singular imperative of попробовать.

It means:

• try
• have a try
• try to...

So попробуй перезапустить устройство means:

• try restarting the device
• or more literally, try to restart the device

This is something you would say to one person in an informal or neutral setting, such as in instructions or conversation.

Попробуй is used for:

• one person
• informal singular

Попробуйте is used for:

• plural you
• or formal singular

So:

• попробуй = try (you, one person, informal)
• попробуйте = try (you all / you, formal)

If this were a polite instruction to a customer, you might often see:

• Если курсор не двигается, попробуйте перезапустить устройство.

This is about verb aspect.

• перезапустить = perfective
• перезапускать = imperfective

After попробуй, Russian often uses the perfective infinitive when talking about a single complete action to attempt.

So:

• попробуй перезапустить устройство = try to restart the device (one complete restart)

If you used перезапускать, it would sound more like an ongoing/repeated process, which is not the usual idea here.

The prefix пере- here gives the sense of again or re-.

Compare:

• запустить = to start / launch
• перезапустить = to restart / relaunch

So перезапустить устройство literally means something like start the device again.

Устройство is in the accusative case, because it is the direct object of перезапустить.

For many neuter nouns, the accusative singular looks the same as the nominative singular.

So:

• устройство = device (nominative)
• перезапустить устройство = restart the device (accusative, same form)

That is why the form does not change.

Yes. Russian present tense often covers both ideas.

So не двигается can be understood as:

• isn’t moving
• doesn’t move

In this context, English usually prefers isn’t moving, because it sounds more natural for a computer problem.

Russian has no articles like the or a/an.

So:

• курсор can mean the cursor or a cursor
• устройство can mean the device or a device

The exact meaning comes from context. In this sentence, English naturally uses the because we are talking about a specific cursor and a specific device.

The given order is the most natural and standard:

• Если курсор не двигается, попробуй перезапустить устройство.

Russian word order is more flexible than English, but not all changes sound equally natural.

For example, you could say:

• Попробуй перезапустить устройство, если курсор не двигается.

This still means the same thing: Try restarting the device if the cursor isn’t moving.

So the order can change, but the original version is a very normal way to give this kind of instruction.