waifai no setuzoku ga warui node, pasokon wo saikidousimasita.

の links two nouns together.

• ワイファイ = Wi-Fi
• 接続 = connection

So ワイファイの接続 means the Wi-Fi connection or Wi-Fi connectivity.

This is a very common pattern in Japanese:

• 日本語の先生 = Japanese teacher
• 学校の名前 = school name
• ネットの速度 = internet speed

Here, ワイファイの接続 is the thing being talked about.

が marks the thing that has the property 悪い.

In this sentence:

• 接続が悪い = the connection is bad

So が is marking 接続 as the thing whose condition is bad.

A helpful way to think about it is:

• X が 悪い = X is bad

Other examples:

• 気分が悪い = I feel sick / My condition is bad
• 頭が痛い = My head hurts
• 電波が弱い = The signal is weak

Yes, 悪い literally means bad, but in this sentence it is more naturally understood as:

• poor
• not good
• unstable
• having problems

So ワイファイの接続が悪い means something like:

• The Wi-Fi connection is bad.
• The Wi-Fi connection is poor.
• The Wi-Fi isn’t connecting well.

In Japanese, 悪い is often used in a broad, everyday way for problems in quality or condition.

ので means because or since.

In this sentence:

• ワイファイの接続が悪いので、パソコンを再起動しました。
• Because the Wi-Fi connection was bad, I restarted the computer.

Compared with から, ので usually sounds:

• a bit softer
• more explanatory
• a little less direct

Compare:

• 接続が悪いので、再起動しました。
  Because the connection was bad, I restarted it.
  → sounds explanatory and natural

• 接続が悪いから、再起動しました。
  Because the connection was bad, I restarted it.
  → also correct, but slightly more direct/conversational

Both are possible, but ので fits nicely in this kind of calm explanation.

This is a very common learner question.

Japanese often uses the plain non-past form before ので to describe the reason or situation surrounding an action, even when the main verb is in the past.

So:

• 接続が悪いので、再起動しました。
  Because the connection was bad, I restarted the computer.

This is natural.

You could also say:

• 接続が悪かったので、再起動しました。

That also works, and it emphasizes that the bad connection was clearly a past state.

Very roughly:

• 悪いので = because the connection is bad / was bad at that time
• 悪かったので = because the connection was bad

Both can be correct depending on context, but the original sentence is perfectly normal.

再起動しました means restarted or rebooted.

It breaks down like this:

• 再 = again / מחדש
• 起動 = startup / booting up
• する = to do
• しました = polite past form of する

So:

• 再起動する = to restart / reboot
• 再起動しました = restarted / rebooted

This word is very common in computer and phone contexts.

Examples:

• スマホを再起動してください。 = Please restart your smartphone.
• ルーターを再起動した。 = I restarted the router.

を marks the direct object of the verb.

Here, the verb is:

• 再起動しました = restarted

So the thing being restarted is:

• パソコン = computer

Therefore:

• パソコンを再起動しました = restarted the computer

This is the normal pattern:

• スマホを再起動する = restart the smartphone
• アプリを再起動する = restart the app
• ルーターを再起動する = restart the router

In everyday Japanese, パソコン is extremely common and usually means personal computer.

• パソコン = PC / personal computer
• コンピューター = computer

In many daily situations, Japanese speakers are more likely to say パソコン when talking about a laptop or desktop.

So this sentence sounds very natural.

A rough comparison:

• パソコン = the normal everyday word for a computer you use at home or work
• コンピューター = a broader or sometimes more technical word

Yes. ワイファイ is a common katakana rendering of Wi-Fi.

You may also sometimes see:

• Wi-Fi
• wifi in informal writing online

But in Japanese text, ワイファイ is very normal and easy to understand.

People also sometimes talk about related words such as:

• 無線LAN = wireless LAN
• ネット = internet (casual)

Depending on context, a person might say:

• ワイファイが弱い = The Wi-Fi is weak
• ネットの調子が悪い = The internet is acting up

Japanese often leaves out subjects when they are obvious from context.

So even though English says:

• I restarted the computer

Japanese can simply say:

• パソコンを再起動しました。

The listener usually understands who did it from the situation.

In this sentence, the omitted subject is most naturally I, because the speaker is explaining their own action:

• Because the Wi-Fi connection was bad, I restarted the computer.

This omission is one of the most common features of natural Japanese.

Yes. A casual version would be:

• ワイファイの接続が悪いので、パソコンを再起動した。

Or even more casually:

• ワイファイの接続が悪かったから、パソコン再起動した。

Changes:

• しました → した for plain past
• ので can stay, or change to から
• In casual speech, particles are sometimes dropped, though that depends on how informal the speaker is

The original sentence is polite and natural.