一、首先檢視系統的運作級别以及是否安裝了桌面環境
1、使用指令 runlevel 檢視目前的運作級别 ，如圖所示
2、使用指令 yum grouplist | more 檢視是否安裝了桌面環境的元件，如圖所示
二、再次從上面分析的結果看到，目前運作級别是3，而且也沒有安裝桌面環境的軟體。
然後我們使用指令檢視一下桌面有哪些桌面環境的軟體，然後裝顯示出來的軟體元件就可以了。例如：
[root@localhost ~]#[root@localhost ~]# yum grouplist | more
Loaded plugins: fastestmirrorSetting up Group ProcessLoading mirror speeds from cached hostfile
* base: mirrors.usc.edu * extras: centos.mirror.ndchost.com *
updates: mirror-centos.hostingswift.com
Installed Groups: E-mail server Security Tools Storage
Availability Tools iSCSI Storage Client
Available Groups:
Additional Development
Backup Client Backup Server
Base CIFS file server
Client management tools
Compatibility libraries
Console internet tools
Debugging Tools
Desktop
Desktop Debugging and Performance Tools
Desktop Platform
Desktop Platform Development
Development tools
Dial-up Networking Support
Directory Client
Directory Server
Eclipse
Emacs
FCoE Storage Client
FTP server
Fonts
General Purpose Desktop
Graphical Administration Tools
Graphics Creation Tools
Hardware monitoring utilities
High Availability
High Availability Management
Identity Management Server
Infiniband Support
Input Methods
Internet Applications
Internet Browser
Java Platform
KDE Desktop
Large Systems Performance
Legacy UNIX compatibility
Legacy X Window System compatibility
Load Balancer
Mainframe Access
Messaging Client Support
MySQL Database client
MySQL Database server
NFS file server
Network Infrastructure Server
Network Storage Server
Network file system client
Networking Tools
Office Suite and Productivity
PHP Support
Performance Tools
Perl Support PostgreSQL
Database client
PostgreSQL Database server
Print Server
Printing client
Remote Desktop Clients
Resilient Storage
Ruby Support
SNMP Support
Scientific support
Server Platform
Server Platform Development
Smart card support
System Management
System administration tools
TeX support Technical Writing
TurboGears application framework
Virtualization
Virtualization Client
Virtualization Platform
Virtualization Tools
Web Server
Web Servlet Engine
Web-Based Enterprise Management
X Window System
Available Language Groups:
Catalan Support [ca]
Chhattisgarhi Support [hne]
Chichewa Support [ny]
Chinese Support [zh]
Coptic Support [cop]
Croatian Support [hr]
Czech Support [cs]
Danish Support [da]
Dutch Support [nl]
English (UK) Support [en_GB]
Esperanto Support [eo]
Telugu Support [te]
Tetum Support [tet]
Zulu Support [zu]
Done
===========================================
從上面的軟體組資訊，挑選與桌面環境有關的軟體組，然後安裝即可，我下面選擇的軟體組與輸入法還有字型等桌面環境需要用到的供大家參考一下。
yum groupinstall -y "Desktop" "Desktop Platform" "Desktop Platform Development" "Fonts" "General Purpose Desktop" "Graphical Administration Tools" "Graphics Creation Tools" "Input Methods" "X Window System" "Chinese Support [zh]" "Internet Browser"
後面的是安裝軟體過程，需要等等一陣時間。
三、安裝好了桌面環境的軟體，然後再修改一下系統的啟動級别 為 5
編輯/etc/inittab檔案，修改啟級别為5，如下圖，然後重新啟動就可以進入桌面環境了。因為我這是遠端環境的，隻是運用了指令行，可以使用VNC進行桌面環境的遠端。
四、重新開機的過程中，設定一下桌面環境的幾個參數就可以正常進入登陸界面了，謝謝。