It looks like you've gotten a lot of opinion about defrag,etc.
While I agree that it is preferable to fix the freezing issue first, the assertion that defrag is obsolete is not accurate (even Miscrosoft recommends defrag, which is exactly why they include and keep updating the built-in defrag utility since Windows 98 -- even in Win 7 , so there really should not be any question about whether or not it is needed.....)
As for how long it should take to de-frag ,etc. here is a rundown of reasons why the defrag may not be working properly (and even why it may be freezing up):
0. There is malware on the system. Solution: Run an AV check and also a spyware check.
00. The disk is heavily fragmented. Solution: Run a defrag (it may take a LONG time if it's never been done before (I've seen some reports of 3-4 days, but that's probably very unusual. If the defrag won't run or takes longer than 1-2 days, see below for possible reasons).
1. The disk is too full (you need at least 15% free space, sometimes 20%). Solution: Delete unneeded files and programs till you have more than 20% free space.
2. The disk is damaged and needs to be repaired (possibly your "Disk Integrity" message). Solution: Open "My Computer" and right click on the drive you want to check. Select "Properties" and click on the "Tools" tab. Select "Check now" to check the disk for errors. Select both options and click start (it may take a while and the PC may re-start so it can do the check at boot time).
3. Disk Defragmenter may be corrupted, needing a correction. Solution: Open System Restore and restore to a point before you started having problems with the PC.
4. Disk Defragmenter may no longer be on the system or is so corrupted that it needs a re-install. Solution:
a. Open the "Start" menu.
b. Type "%Windir%\Inf" in the "Search" box and press "Enter".
c. In the window that opens, find the file named "dfrg.inf".
d. Right-click on "dfrg.inf" and "Install." Then attempt the defrag again.
5. There are other programs running that interrupt the built-in defragmenter. Solution: Close all running programs (A/V, Spyware, etc.). If you suspect there may be some programs running in the background, use Ctrl+Alt+Delete and select "Start Task Manager" Under the "Applications" tab you will find a list of all running applications -- you can close these by selecting "End Task."
6. If still no luck, try disabling the screen saver when running Disk Defrag (you should pretty much leave the system alone when running the built-in defrag utility).
7. If still no go, try running the defragmenter in Safe Mode. If it runs, something is interfering with it and tracking the interference down may not be easy.
You should consider downloading a free trial of a commercial defrag tool.
Personally I use Diskeeper; it is more robust and it works in the background so you can use your PC. The latest edition also prevents fragmentation.
You can get a free trial at: http://www.diskeeper.com
Bill R TechSpec
PS: If these do not resolve yur issue, let me know here and i can give you some more drastic measures. My guess is that step 3 will solve everything, but if not and you do all 7 steps and still nothing there are more steps to consider. Let me know....