The way I understand it , to "format" means to erase everything. I think you mean to "defrag" the hard drive. I think "system restore" will also cause you to lose things like passwords and maybe even some files & pictures. Better wait for someone more computer smart then me to answer though. I have 2 defrag programs , one under my Norton security program that just does a quick 5 minute defrag and then the one under my Windows admin that takes over an hour sometimes to finish. I collect a lot of pictures through the month (over 1000) and at the end of the month , clean them out(save) to DVD's. I also down load everything in my PC at the end of the month to an external hard drive in case my computer crashes , I can recover everything. It's after I'm done with all that that I do a Window's defrag.
Formatting will remove everything on the partition of the disk. It can be undone if it is not overwritten with new data so don't consider it a secure way to clear the disk before discarding it though. However, I suspect that @Uncle Frank is right and you mean defrag. The more often you do it the shorter amount of time it takes to get done. However, I would not do this more than once every couple of weeks. If you have significant fragmentation (greater than 10%) between the defrags with that schedule you may have some others issue going on. Also, this only really applies to spinning disks, not to SSDs. SSDs handle data differently and there is not really a performance boost/penalty based on where the information is written on the filesystem.
When I get a new computer I yank out the old hard drive and drill about 10 or 15 holes all the way through it and I still have a big VCR tape eraser that I run over it. I figure I'm safe then , LOL. I love external hard drives and how much you can store on them. I back up to them at the end of each month and my desk top has a built in backup storage area also. In all the years I've been computing , I've only had a major crash once , knock on wood.
For secure erasure I use DBAN ( Darik’s Boot and Nuke – DBAN ). Its an open source software that has been around for a long time and you can boot off of a CD/DVD or bootable USB drive and if you don't know what you are really doing you just select the drive(s) you want wiped and choose the "autonuke" option. This will wipe the drive to DoD (unclassified info) standards with multiple passes (3 by default) so that you can be sure nothing can be recovered. That way you don't have to physically destroy the drive.