It is very simple.
Click Application –> Ubuntu Software Center –> Get software
Then Search for GIMP
Click install to install gimp.
( or )
Open a terminal
Go to root login prompt
verman@verman-desktop:~$ sudo -i
type apt-get install gimp
root@verman-desktop:~# apt-get install gimp
Reading package lists… Done
Building dependency tree
Reading state information… Done
The following extra packages will be installed:
gimp-data libbabl-0.0-0 libgegl-0.0-0 libgimp2.0 libmng1
Suggested packages:
gimp-help-en gimp-help libgimp-perl gimp-data-extras
The following NEW packages will be installed:
gimp gimp-data libbabl-0.0-0 libgegl-0.0-0 libgimp2.0 libmng1
0 upgraded, 6 newly installed, 0 to remove and 156 not upgraded.
Need to get 7,598kB of archives.
After this operation, 54.2MB of additional disk space will be used.
Do you want to continue [Y/n]? Y
Get:1 http://in.archive.ubuntu.com/ubuntu/ lucid-updates/main libgimp2.0 2.6.8-2ubuntu1.1 [594kB]
Get:2 http://in.archive.ubuntu.com/ubuntu/ lucid-updates/main gimp-data 2.6.8-2ubuntu1.1 [1,981kB]
Get:3 http://in.archive.ubuntu.com/ubuntu/ lucid/main libbabl-0.0-0 0.0.22-1build1 [72.2kB]
Get:4 http://in.archive.ubuntu.com/ubuntu/ lucid/main libgegl-0.0-0 0.0.22-0ubuntu4 [329kB]
Get:5 http://in.archive.ubuntu.com/ubuntu/ lucid/main libmng1 1.0.9-1ubuntu1 [209kB]
Get:6 http://in.archive.ubuntu.com/ubuntu/ lucid-updates/main gimp 2.6.8-2ubuntu1.1 [4,413kB]
Fetched 7,598kB in 24s (305kB/s)
Selecting previously deselected package libgimp2.0.
(Reading database … 122714 files and directories currently installed.)
Unpacking libgimp2.0 (from …/libgimp2.0_2.6.8-2ubuntu1.1_i386.deb) …
Selecting previously deselected package gimp-data.
Unpacking gimp-data (from …/gimp-data_2.6.8-2ubuntu1.1_all.deb) …
Selecting previously deselected package libbabl-0.0-0.
Unpacking libbabl-0.0-0 (from …/libbabl-0.0-0_0.0.22-1build1_i386.deb) …
Selecting previously deselected package libgegl-0.0-0.
Unpacking libgegl-0.0-0 (from …/libgegl-0.0-0_0.0.22-0ubuntu4_i386.deb) …
Selecting previously deselected package libmng1.
Unpacking libmng1 (from …/libmng1_1.0.9-1ubuntu1_i386.deb) …
Selecting previously deselected package gimp.
Unpacking gimp (from …/gimp_2.6.8-2ubuntu1.1_i386.deb) …
Processing triggers for hicolor-icon-theme …
Processing triggers for man-db …
Processing triggers for desktop-file-utils …
Processing triggers for python-gmenu …
Rebuilding /usr/share/applications/desktop.en_IN.cache…
Processing triggers for python-support …
Setting up libgimp2.0 (2.6.8-2ubuntu1.1) …
Setting up gimp-data (2.6.8-2ubuntu1.1) …
Setting up libbabl-0.0-0 (0.0.22-1build1) …
Setting up libgegl-0.0-0 (0.0.22-0ubuntu4) …
Setting up libmng1 (1.0.9-1ubuntu1) …
Setting up gimp (2.6.8-2ubuntu1.1) …
Processing triggers for libc-bin …
ldconfig deferred processing now taking place
root@verman-desktop:~#
Now gimp installed in my PC and it works fine.

I Love GIMP.

