為何電腦好慢?

1. 如中蠕蟲 (worms) 一類腦毒就會，因為它不斷重複以幾何級數去增加自己數量，最後會把你硬碟存量擠滿。

2. 內置硬碟一般需要有 15% 空間方可令軟件檔案更新、轉換(軟件程式正常運作過程)，你只有 1% 空位，不僵化已算幸運。

3. 還原會把你機內所有第三方軟件(即只留下視窗系統及出廠附送軟件)及當中連帶一切設定(登記密碼，桌布，顏色等等回家後所做一切)全部洗掉，還原後必須重新安裝一切需用(如燒錄、辦工室、打印機等等)軟件。建議做前必須把硬碟內一切功課(文件檔，音樂、相片等等)抄出(用外置硬碟等)做備份，洗機後抄回，否則一切全失，痛不欲生。

如還原至出廠狀態而毒只存在軟件系統 (視窗)，應可消除。但現下放毒手法極其高明及多元化，可以同時 (a) 阻止廠法還原， (b) 毒亦可滲入機硬件(底板，記憶體，快存記憶體等等)，如是的話，洗機只可針對軟件，硬件乃另一回事。

以上資料只作推測及提供可能性與各項需知、處理方法，事實須你自己查証然後應對。

4. 其他方法。
先用掃毒軟件清機，排除蠕蟲因素。再用免費軟件如 Ccleaner (下載 Free 一項) 去清理機內一切廢檔，如完後有超過 15% 空位便可回常，如欲再進一步，可把機內大型檔案如電影，歌檔夾、短片檔夾等抄入一個外置硬碟內(現時售價合理)，所得空間會令你驚異，如你機資料超多，加碟只是遲早事。原廠法還原雖然第一步方便(多時為一鍵還原設計)，但之後須勁費時、心、力去設砌回復你須用之其他程式軟件，以上已解釋清楚，應可作出選擇。提示︰那 Ccleaner 非常可靠好用，每星期最少做一次。因每天普通上網亦遺積大量廢檔，阻塞運作。

There are many reasons that makes the PC slow:
1. HDD is really slow. The PC start slow and runs slow is normal
2.HDD 99% full is also the reason that slows down the pc
3. Factory reset maybe can help a bit, but if you get a virus like cryptolocker, factory reset may not work.
4. To keep your pc fast, try to buy a SSD to replace your HDD as your C drive and see if it's faster.
5.Don't put too much things in your C drive
6.Don't save things in C Drive that is downloaded by BitTorrent

Normally the PC will slow down obviously after HDD fill up over 85% of the capacity !

It needs some space reserve for the Vitrual memory + sweep...

硬碟爆棚你又唔願意清理，可以換新硬碟重灌，灌完就新嘅一樣，舊硬碟中毒或爆棚，都冇關係。

1. There are too many reasons why a computer is slow. Virus may be one of those.

2. Definitely yes.

3. Yes and Yes. Factory Restore basically erases everything and restore the computer based on the image stored in the restore partition.