Hi,
I've uninstalled Perl and now I am trying to install it one more time, unfortunately I get:

# aptitude install perl
The following packages will be REMOVED:
bzip2{u}
The following partially installed packages will be configured:
man-db
0 packages upgraded, 0 newly installed, 1 to remove and 0 not upgraded.
Need to get 0 B of archives. After unpacking 160 kB will be freed.
Do you want to continue? [Y/n/?] y
debconf: Perl may be unconfigured (Can't locate strict.pm in @INC (@INC contains: /etc/perl /usr/local/lib/perl/5.10.1 /usr/local/share/perl/5.10.1 /usr/lib/perl5 /usr/share/perl5 /usr/lib/perl/5.10 /usr/share/perl/5.10 /usr/local/lib/site_perl .) at (eval 1) line 2.
BEGIN failed--compilation aborted at (eval 1) line 2.
) -- aborting
(Reading database ... 43983 files and directories currently installed.)
Removing bzip2 ...
Setting up man-db (2.5.7-8) ...
Can't locate strict.pm in @INC (@INC contains: /etc/perl /usr/local/lib/perl/5.10.1 /usr/local/share/perl/5.10.1 /usr/lib/perl5 /usr/share/perl5 /usr/lib/perl/5.10 /usr/share/perl/5.10 /usr/local/lib/site_perl .) at /usr/share/debconf/frontend line 5.
BEGIN failed--compilation aborted at /usr/share/debconf/frontend line 5.
dpkg: error processing man-db (--configure):
subprocess installed post-installation script returned error exit status 2
configured to not write apport reports
Errors were encountered while processing:
man-db
E: Sub-process /usr/bin/dpkg returned an error code (1)
A package failed to install. Trying to recover:
Setting up man-db (2.5.7-8) ...
Can't locate strict.pm in @INC (@INC contains: /etc/perl /usr/local/lib/perl/5.10.1 /usr/local/share/perl/5.10.1 /usr/lib/perl5 /usr/share/perl5 /usr/lib/perl/5.10 /usr/share/perl/5.10 /usr/local/lib/site_perl .) at /usr/share/debconf/frontend line 5.
BEGIN failed--compilation aborted at /usr/share/debconf/frontend line 5.
dpkg: error processing man-db (--configure):
subprocess installed post-installation script returned error exit status 2
Errors were encountered while processing:
man-db

it seems that system is in never ending loop.

I need more information. What linux distribution are you running? Is this problem on a desktop, workstation or on a server?

In general it is not a good idea to remove perl from a linux box, I guess. If you need a different version of perl for a particular purpose you can install a second version, i. e. to /usr/local/yourPerl
If your distribution has a recovery mode try to use that to reinstall the original perl.

Debian Squeeze.

Not in Debian. I've made this many times in Slackware without any problems.

Still knowing little, I get the impression that your problems are caused by suddenly missing package dependencies and that, when you originally uninstalled perl, you broke many other programs on your system. It simply might be best to hook the hard drive from that computer up to another computer as a slave, retrieve your data and do a complete reinstall from scratch on that computer. In the future, you might want to get a GUI front end for the package manager for your debian squeeze so that you can see exactly what you are getting into before you actually start doing anything. My understanding is that debian uses apt for its package management.

As usual, https://wiki.debian.org/PerlFAQ