|Safe Mode does not load a lot of things that are loaded when you boot normally.|
Lots of programs that did not come with Windows have (a) module(s) that interfere(s) with Defrag and make it restart over and over again, when you try to run Defrag when you have booted normally -all, or most of, those programs do not load in Safe mode. It often takes the least amount of time for Defrag to finish in Safe mode.
When Defrag restarts it continues where it last had degfragged in the particular session, but it takes a while to get back there..
Defrag is a program that helped a lot when computers ran much slower than they do now, but it's not of much help for modern computers.
If you're running Defrag because your Windows installation is running MUCH slower than it once did, running it won't help much - there are lots of things that can slow down Windows that running Defrag cannot fix.
E.g. What is the size of your partition Windows is running from, which is usually C ? How much free space does it have on it ?
If that partition is too full, e.g. if there is less than about 10% free space on it, then Windows will run MUCH slower than it is otherwise capable of running.
"Why firewall error"
If you are connected to your internet connection via a router or a combo router / high speed modem, most people DO NOT need a third party software firewall - the router has a built in "hardware" firewall - it's default settings are usually sufficient, or you can custom add on to them in the router's configuration settings
If you don't NEED a third party software firewall (one that did not come with Windows) , then you're probably better off without it , as far as the annoyance of it's messages and having to figure out what it's messages mean are concerned.
If you feel you DO need a third party software firewall, then you're better off if you DISABLE it from running when you're doing certain thing, such as running Defrag.
"Second drive logical on fat32 when computer ntfs"
It doesn't matter whether the partitions are using FAT, FAT32 or NTFS (software) partitioning, regarding running Defrag, and most programs .
However, if you're experiencing errors in Windows that you can't determine a reason for, you may have a failing hard drive
Check your hard drive(s) with the manufacturer's diagnostics.
See the latter part of response 1 in this:
If you don't have a floppy drive, you can get a CD image diagnostic utility from most hard drive manufacturer's web sites, but obviously you would need to make a burned CD, preferably a CD-R for best compatibility, on another computer if you need to.
Seagate's Seatools will test (almost) any brand of hard drive.
Do the long test.
The bootable Dos versions of SeaTools can be used even if Windows is not working properly.
If the hard drive itself tests okay, any data problems found can be fixed, one way or another.