malay, when you start installing linux you will first of all get boot options. All distros give you an option to turn off acpi (no acpi or acpi off depending on the distro.) But if you are really unsure of doing all these, I suggest you pick Mepis 3 or the latest version Mepiis 6. It asks you a minimum no of questions. HaahN yes, if you are dual booting with windows, install windows first. Whether you have already created partitions on the whole disk or not does not matter. But make sure that you remove all your data from one partition and leave it blank. Mepis works with as little as 2 Gb hard disk ( yes i am not joking . My Mepis 6 has not grumbled so far unlike Fedora or Mandriva which complain that I do not have enough disk space. I have had 3 OSes ( win 98, XP and Mepis 3 on a mere 15 Gb hard disk and 128 Mb ram ) And Mepis is not too demanding on ram either. It is the Desktop tht gobbles up space like anything. Also ensure that you do not have more than three primary partitions on your disk. ( The maximum primary partitons you can create are four. One is needed for linux, and you can have the other three for other uses.) If your hardware is ok mepis will start ( not install ) and you can test it and enjoy it till you are familiar with linux ( Mepis comes from the debian stable and is stable ) If you are happy with linux ( you should be by now) you will find the installation icon on your desktop ( install me) click it. The installation starts by asking you for the root password . Type it. installation continues , asking you to suggest a partition for linux . As you donot yet have a Ext 2 or 3 partition select "Run QT Parted " ( usually the second row on the right side). This will bring up another window shoeing your current hard disk partition status. ( if you have previously emptied one partition, it will shoe up as 100 % or 99 % free) From the drop down menu at the top ( actions) select delete. Then again selct commit . It will ask for confirmation. click Ok . Now your QT parted screen will show a unallocated partition ( whatever size you selected earlier) click on this agin. from the menu select create. It will again ask for confirmation click Ok again. It goes through its routine and now you have an Ext 2 Partition ( needed for linux). close QT parted and Go back to the previous screen Now you should see Mepis showing an available partition in the first row ( if it doesn't scroll down and you will find an ext 2 partition listed and select it by clicking). Dont bother about allocating for /, /user, /home etc. Mepis will auto allocate depending on the disk size. click next at the bottom. Finally Mepis will ask you where to install GRUB ( Grand Unified Boot Loader)simply select MBR ( Master Boot Record)and confirm again when it asks. Now you can sit back ( As microsoft is fond of telling us). with your configuration insytallation should be over in less than 15 minutes. Post installation it will ask for language, ( leave everything at default except language. for he language you can select from the available languages . There are not many so better choose English. Mepis comes only with KDE ( atleast My distro didn't provide desaktop option)). and click to rebbot. when it reboots you have your linux login screen showing boot options. If you had windows it will show up. select linux and enjoy FOSS . And yes GOOD LUCK THIS TIME .

The easiest way to change the acpi boot options would be to temporarily change it at the Grub boot menu.
When your pc starts up, you will see the Grub boot menu, simply type e to edit the highlighted boot OS (you can use the <UP> or <DOWN> cursur keys to scroll to the desired boot OS).
You should then see a new screen that corresponds to the boot OS's options.
For Linux scroll to the kernel line and type e to edit the kernel options line and append acpi=off (or whatever option(s) you want), press <ENTER> to finish editting the line, then b to boot the OS using the changes.
Note that any changes you type here will not be saved to disk, for that you will need to edit /boot/grub/menu.lst and make the changes permanent.

For Lilo, you will need to edit the file /etc/lilo.conf and make the changes there (see man lilo.conf) and don't forget to update the changes by running lilo after saving lilo.conf.
Sorry I can't be more help with lilo, but I don't use it myself, I prefer Grub.

Good luck.

I remeber I had posted another post to this thread may be I forgot to post it. But coming to malay's problem,Knoppix has one of the best hardware detection and configuration set up.
But malay has still not manged to solve his problem it appears. In his later post he said his SMPS fan was not working. It indicates that one of the 12 volt lines may be missing. He has not yet reported whether he had his SMPS checked and repaired. If he has't the problem may still be there and let alone knoppix nothing is likely to work. It would be nice if thread starters reported the developments and the results of the suggestions
( which helped them). Then the thread can be closed and the contents moved to an archieve. anything can be first be looked up in the archieve and if nothing helpful is found there a thread can be started. This saves a lot of repetition and administrative overheads.