You need cloning software, and there are several good ones you can buy. Acronis True Image is one, also Easeus, and others.
However, you may well get good software free! Several HDD makers will let you download their custom cloning software free from their website. They do this as a service to induce you to buy THEIR HDD units, so here's the "hook" in the deal. They don't worry about what old HDD you are getting rid of. But their software will only make a clone copy TO one of their drives. For example, Seagate has Disk Wizard. WD has Acronis True Image WD Edition. Both of these appear to be customized versions of Acronis. Some other HDD makers have their own free utilities.
Make sure you get and read the manual for the software you download. The customized Acronis versions I mentioned above do a LOT more than cloning, so you should learn all their uses. The manuals also will help you with one small problem I've had with them. The most common story is someone who is upgrading to a larger HDD and replacing their older one. (That's not quite your reason for replacement, but that does not matter.)
When you run the cloning tool its first step is to be sure you specify the correct SOURCE and DESTINATI0N units. Don't get these backwards - the DESTINATION unit will get completely wiped out and loaded with new stuff, so make sure it is the NEW HDD you bought, not your old one! Next it will propose a bunch of settings for the structure of the new HDD. The steps it is preparing for are Partitioning and Formatting. A Partition is a chunk of the HDD that will be treated by Windows as a "drive" with its own letter name. You can have one or a few of these Partitions on one HDD unit, and you can set their size when they are created. But they are hard to change later. Quite commonly the user actually wants ALL of the new HDD to be one large Partition. But the default settings often presented to you make the Partition size on the new HDD the same size as the old one. If you approve this, you will have spare space called "Unallocated Space" on your new HDD that you CAN use to create a second (or more) Partition on, and then use it as a separate "drive". BUT if that is not what you want - if you want the WHOLE new HDD to be in the Partition - you can use the menus to change the settings to what you want. The manual can help you spot how to do this.
The whole idea of cloning is that you make a complete copy of absolutely everything on your old HDD, including putting certain key files in just the right places, so that it can become your new boot drive known as C:. Once the clone is made, you can connect it to your mobo in the same place as the old drive was, and remove the old HDD completely. Your machine will behave just the same as before, except that the C: drive will probably be a different size.
IF your old HDD actually has more than one Partition on it to begin with, the default settings are different. Most commonly they propose to make Partitions on the new HDD to match all the ones on the old one, but they set each new Partition's size in Proportion. That is, if the old drive's first Partition took up 35% of the space on that HDD unit, the cloning software will propose that its clone copy on the new HDD will take up 35% of the NEW HDD's space, whatever that is. Etc. Often this, too, is not what you want. Again, using the menu systems you can specify the size YOU want for each Partition on the new HDD, as long as the total is not larger than the unit.
