网友作文三：

Dear all:
The file system will shtudown [1]due to system maintainance next Friday.
It will take a full day to finish this job.[2]
Please do not acccess the [3]file server that day and backup your files one it[4].
_________________________________________

[1]够干练了，语法错误多。 Be shut down
[2]去掉
[3]Access to
[4]On it ?

网友作文四：

From: office Manager
To: all staff
Subject: upgarde of computer system
As our computer system need to be upgraded, we have arranged the contarctors to upgrade the them [1]on Wedesday. On that day all computers should be shutted down for a full day, so you need arrange some alternative work for that day.

_________________________________________

[1]第一: 不要重复使用前面已经用过的词；第二：指代错误，前面说的system 是单数，怎么到这里变成了them? 合成一句：as we have arranged the contractor to upgrade our computer system.

网友作文五：

All of the staff:
We have arranged for contractors to upgrade our computer system, so it will be shut down from 0:00,1st, Jan. to 0:00, 2nd, Jan. Please prepare alternative work for the day.
If you have any problem, you can contact with us at any time.

_________________________________________

[1]Anytime 就可以了。 整个memo 写得很清晰干练，很好！