I would like to ask how and if it is possible to clone my boot hard drive (windows7 one) to another hard drive of DIFFERENT model.
Will the pc then be able to boot and work normally from the new hard drive?
Is there anything I must be careful of in the prescess?
Just to be sure what you ask, I assume you want to change from one hard drive to another (probably larger capacity) for your C: boot drive, but continue to use it in the same machine, not in a different computer with different motherboard and other components. If that's wrong, post what you plan for better advice. But if I'm right, the tasks are pretty easy and there are good free tools for this.
The key is that most hard drive manufacturers know that many of their customers are doing exactly this - replacing their C: drive with a larger one - and they want to make it really easy so they help you by giving you the cloning tools as a free download from their websites. The small trick to watch out for is that the free software will usually make a clone copy TO a HDD from that maker only - they really don't care whose old drive you are replacing. So, for example, if you buy a new HDD made by Seagate or Maxtor (owned by Seagate), go to the Seagate site, download their Disk Wizard package, and install it on your current C: drive. On the other hand, if it's a WD new disk, get Acronis True Image WD Edition from the WD website. Both are customized version of Acronis software. It is very good and does a LOT other than cloning, so be sure to download also the manual (if it's not already in the package) and read it. Other HDD makers have similar utilities.
There is one thing you should check before running the software and making your clone. Many people in your situation have older HDD's smaller than 128 GiB and have never had this problem, but it can emerge as you migrate to a larger drive. To use any HDD larger than 128 GiB (Windows' way of counting) or 137 GB (HDD makers' specs) you must have a feature called "48-bit LBA Support" in three places: the HDD itself (obviously will be there on a large drive unit), the HDD controller on your mobo, and the OS. For the mobo controller and BIOS, ALL SATA systems have it, so if you're installing a SATA drive you have no worry on this point. It is only a potential issue if you are installing an IDE drive on a mobo made earlier than about 2000; in that case, check with the mobo maker's website to find out if the BIOS has "48-bit LBA Support", and NOTE that just plain "LBA Support" is not enough. On the Operating System side, Windows XP original version did NOT have this feature, but it was added in its Service Pack 1 and maintained in all subsequent SP's for XP, and in Vista and Win 7. For you with Win 7, you have no problem on this part.
Once you're satisfied that your system can handle a large disk, the cloning with the free utility is relatively easy. There are a few points to watch for, though.
1. Ensure the software is installed on your current C: drive. Disconnect power to your machine, open it up, mechanically mount the new drive in the case and connect it to its power and data cables. Close up, boot into BIOS Setup and just check that the port it is connected to is Enabled. There is also in this area a place to set the port mode. Simplest advice I have is, look at the mode setting for your existing C: drive (IDE Emulation, native SATA, AHCI, or whatever) and make the new drive's port the same. Check that the BIOS has detected this new drive device. Save and Exit to finish the boot. Do not bother looking in My Computer for the new drive - it won't be there because it has not been prepared for Windows to use.
2. Start the cloning package. Be EXTRA careful to identify the DESTINATION drive as the new one, because this process will DESTROY all data on the DESTINATION unit before putting new stuff on it. Also be sure the SOURCE drive is your existing C: drive.
3. Look around the menus for options - reading the manual BEFORE helps this step a LOT. There are three steps that will be done for you, probably combined into one job so you're not aware of the details. The first is to Create a Primary Partition, the second is to Format that Partition, and the last is to copy absolutely EVERYTHING from the old C: drive to the new one. Just briefly, a Partition is a chunk of the HDD's space defined for use as one "drive" that Windows will give a letter name to and use. While it is possible to define several Partitions on one physical HDD unit, Windows would treat each of them as if they were separate "drives". Some people like to create and use more than one Partition on a large HDD unit; others like to use ALL of the space as one Volume or "drive". Some even create one or more Partitions smaller than the whole space and leave some space unassigned for later use.
4. You will want it to Create a Primary Partition (the first Partition on the HDD) AND to make it BOOTABLE so you can boot from it. For size, there are four options. One (often the default, so watch out for this) is to make the new one on the DESTINATION drive the same size as the old one. For most people migrating to a new larger HDD unit this is NOT the right choice. A second choice is to make the new Partition a size you manually specify. A third choice (really, part of the second) is to make it the whole space available. The fourth choice, IF your old drive already has more than one Partition on it, is to clone all the old partitions to the new drive and make the new sizes Proportional to what was on the old drive. For many people, the straightforward choice is to make one Partition that uses up ALL of the HDD's space, but you will have to choose that - it may NOT be the default option.
5. You have to specify the File System to be installed. Choose NTFS unless you KNOW you need FAT32 for something.
6. During the Format step there are two choices. A Quick Format will do all that is necessary in about 10 to 15 minutes; then the disk is ready to put files on it. A Full Format does the Quick job first, they exhaustively goes through the entire disk testing its sectors and marking off any with errors so they are not used. This will take MANY hours to do. It usually is not necessary for a brand new HDD unit, but you can anyway if you have lots of time and patience and wish to be extra sure.
7. When all the options are set, run the task. It will take a while, depending on how much stuff there is to clone from your old drive. When it has finished successfully, exit out of the software, shut down and disconnect the power cord. I recommend you go into the case, disconnect both power and data cables to the old drive, and move the data cable for the new drive to the same mobo port connector the old one was on. Close up and boot up. The machine should boot exactly as it did before, except that when you look in My Computer you should see the C: drive is now a LOT bigger than it used to be. Meanwhile the old drive is sitting there disconnected as a complete backup of your system up to the point of making the clone.
8. After you have run this way for a while and are convinced it is working as planned, you can decide what to do with the old drive. (If there was a bad problem, you always could have put the old drive back in place of the new one.)
If you're using Windows 7 then you can use the built-in "Create a System Image" function of the backup utility. You can use this to back up your OS drive to a backup disk and burn a bootable recovery CD. Then you can boot from the recovery CD to restore the backup to a completely different drive. Once the restore is complete you then boot from the copy you made.
I had no problem doing this with the Win7 RC version to move it from a WD HDD to an Intel SSD - so it will certainly work for different disk types.