recently,i installed some packages on my kubuntu system. it was fine then. next day when i started my pc, it won't boot. it stopped at some point of booting. however when tried in recovery mode it started.
what could be the problem and how to fix it.

2.now when i've started my system in recovery mode, cdrom and usb drives are not automatically detected. i managed to mount cdrom from shell but i could not mount my pen drive. why is this happening? otherwise also how do i mount my pendrive. please give some links or something. i'm interested in knowing these things really work.

3.can we fix broken packages?? how?

4.some time back i tried to install ubuntu on my machine. during installation it asked abt the resizing the partitions. does the resizing affect other OSs on system.(i was not sure so i quit the installation)

PPLEASE DETAILED ANSWERS(OR LINKS)

Exact messages are required. Possibly your X settings are changed ?

Describe h/w

Post output of

#lspci
See the system logs
enable boot logs and post output



#sudo mkdir /media/dvdrw
<your password>
#sudo mount -t iso9660 /dev/dvdrw /media/dvdrw

#sudo mount -t vfat /dev/sdc1 /media/disk
(check device name ... it may be /dev/sdb1 too, mount point should exist or you make them)
(penrive)

See the Ubuntu Wiki for more details

3.can we fix broken packages?? how?

You can fix broken packages in your synaptic Package Manager.

For mounting drives this may help.

http://www.psychocats.net/ubuntu/mountwindows
http://www.psychocats.net/ubuntu/mountlinux

4.some time back i tried to install ubuntu on my machine. during installation it asked abt the resizing the partitions. does the resizing affect other OSs on system.(i was not sure so i quit the installation)

No.

while booting it gives errors like "display manager is not working"
and "hardware abstraction layer hald"....what does this mean?

i want to present a paper(paper ppt competition) in our college(not like the research paper). i like linux in general,and would like to know more about it.
can anyone suggest a topic(a bit uncommon) on which i could write a decent paper? i'm fairly familiar with linux now, but i know nothing of shell programming,kernel and other linux programming features.