Apt-get :: What about "uninstall"?

Hi all
back again

now i need to "uninstall" some libraries i installed on it

ok,it's easy (i say):
# dpkg -r libpcsclite1
it work (well, i need to remove also libc6 or insert "-F depends")

BUT
whenever i try to do anything (including run dpkg ) it say
-bash:dpkg not found

searching around i discovered it umount (or does'nt recognize anymore) some "useless" directory like /etc /usr /opt etc.
trying to reboot, ofc, will bring me an error and does not backup the directory

so... what's the problem?

Edit
I tried again, and looked at "mount".
this is what i got BEFORE running dpkg:

Code Sample

root@0[root]# mount /dev/root on / type ext2 (rw) /ramdisk on /ramdisk type tmpfs (rw,size=763452k) /UNIONFS on /UNIONFS type unionfs (rw,dirs=/ramdisk=rw:/KNOPPIX=ro,delete=whiteout) /dev/shm on /cdrom type tmpfs (ro) /dev/cloop on /KNOPPIX type iso9660 (ro) /UNIONFS/dev/pts on /UNIONFS/dev/pts type devpts (rw) /proc/bus/usb on /proc/bus/usb type usbfs (rw,devmode=0666) /UNIONFS/dev/hda1 on /mnt/hda1 type ext2 (rw,nosuid,nodev) /mnt/hda1/mydsl/firefox-1.5.0.5.uci on /ramdisk/opt/firefox-1.5.0.5 type iso9660 (ro,loop=/dev/cloop1)

And this is what i got AFTER dpkg -r

Code Sample

root@0[root]# mount rootfs on / type rootfs (rw) /dev/root.old on / type ext2 (rw) /proc on /proc type proc (rw,nodiratime) /sys on /sys type sysfs (rw) /dev/shm on /cdrom type tmpfs (ro) /dev/cloop on /KNOPPIX type iso9660 (ro) /ramdisk on /ramdisk type tmpfs (rw) /UNIONFS on /UNIONFS type unionfs (rw,dirs=/ramdisk=rw:/KNOPPIX=ro,debug=0,delete=whiteout,copyup=preserve) /dev/pts on /UNIONFS/dev/pts type devpts (rw) /proc/bus/usb on /proc/bus/usb type usbfs (rw) /dev/hda1 on /mnt/hda1 type ext2 (rw,nosuid,nodev) /dev/cloop1 on /ramdisk/opt/firefox-1.5.0.5 type iso9660 (ro)

it could be useful to understand what's happening?

Quote (Juanito @ Oct. 24 2007,06:54)

You could use dpkg -L packagename to see a list of the files that were written to dsl. Once you have the list, the problem is to decide which files were added to dsl and which files overwrote existing files in dsl. If you remove a file that overwrote a dsl file that is needed, you could be in a bind...

I did it:

Code Sample

root@0[root]# dpkg -l    Name           Version +++-==============-============== ii  linux-kernel-headers 2.5.999-test7-bk-17 ii  libc6-dev      2.3.2.ds1-22sarge5 ii  libccid        0.9.3-1 ii  libpcsclite1   1.2.9-beta7-5

so... if doing "dpkg -r" make all things going strange, maybe i can't remove it?
can i install (for instance) older version of libpcsclite so to overwrite newer version?

edit
Ops sorry
i just noticed your advice was "dpkg -L" and i did "dpkg -l"
btw, doing as you said:

Code Sample

root@0[root]# dpkg -L libpcsclite1 dpkg: invalid option -- L BusyBox v1.00 (2006.01.20-18:21+0000) multi-call binary Usage: dpkg [-ilCPru] [-F option] package_name