Windows 7: BSOD on startup, system repair not working, Minitool PW screw-up

I'm running a 1.5 year-old DELL Inspiron 15 R with Windows 7 64, a Intel i7 2630-QM, 6GB of RAM and a 750GB drive (I think it's a Western Digital) Since a little while ago (~a month) my windows was terribly slow, ctrl+alt+del didn't work so I manually restarted, same problem, manually restarted again and after this time, windows hung up, but this time when I pressed ctrl+alt+del I got an error message saying that windows could not load emergency options on startup or something like that, so I manually restarted once again only this time, immediatly after the windows flag animation I got a glance of a Blue screen for half a second and then it rebooted, after that I gat a black screen asking me to choose whether I would like to use startuo repair or start windows normally, if I choose the latter, same thing happens (blue screen for a microsecond and then reboot) if I choose to try to recover windows, it loads only a desktop with the default windows 7 wallpaper (blue with leaves and a bird). I have Kubuntu installed on my hdd so I went and googled a lot, I burned another recovery cd, same result as trying to boot from recovery partition (loading files, windows flag, useless desktop).

I ran Kubuntu normally for a few days while I researches more intensely on my problem, some suggested it could be a hardware problem with the HDD but I doubt it, since I could use Kubuntu normally, another post I found suggested to delete the bootcat.cache file, so I backed it up on linux and deleted, it didn't do anything and after the boot up it didn't regenerate. Recently a friend suggested me using the Minitool partition editor to check my windows partition and try to repair it, I did, I ran a disk scan on my windows partition and left it overnight because it started with a speed of ~5300 MB/s and ended up with a speed of around 2500 MB/s after I woke up, it had found 24 errors and was now analyzing with a speed of ~50 MB/s and said it would take 127 days to finish, so I cancelled the exam, I then proceeded to analyze the filesystem but for this I had to set up the letter of the drive, which I could not do since the button for this (Change letter) was blanked out, all my partitions appeared as *:, so I rebooted to try to google some more but this time, it skipped GRUB and went directly to the windows boot options, I rebooted again and same thing, my Linux disappeared, I went to the partition manager and my Linux partition was set as "Logical" and when I tried to open it to analyze the data, nothing showed up.

I used to be calmed about the whole issue since I could access most of my windows files from linux, but since my Linux seems to have disappeared (partition is still there, but is unaccesible) I'm really starting to freak out.

If the PW Surface Scan found errors then your HD has serious problems.

Boot and run the HD maker's HD Diagnostic extended CD scan to get a firm diagnosis. If it passes run Disk Check from the Windows 7 DVD or System Repair Disk Command Line.

First of all, I'm not blaming my problem on the Minitool PW, it is awesome, erasing GRUB was my fault, when I rebuilt the MBR I overwrtote GRUB (found it out after intense googling), second, if my HDD has hardware problems, why is it that my Linux worked just as it always had, no slowing, no errors, nothing. But I will do the manufacturer scanning utility, as I can't use the recovery/installation DVD.

What is the problem booting the Windows 7 DVD or System Repair Disk.

When you set the disk drive first to boot in BIOS, or trigger the disk to boot using the one-time BIOS Boot Menu key given on first screen, are you prompted to Press any Key to boot disk?

Where did you get the disk? How is it burned? Try burning another using the ISO and tool given from Step 5 of Troubleshooting Windows 7 Failure to Start . Make sure Windows 7 is marked active, then with all other HD's unplugged run Startup Repair - Run up to 3 Separate Times

In the recovery partition/cd, it passes the "Windows flag animation" stage and then gets me to a blue backgrond with a movable cursor and nothing else, and in the installation DVD it hangs up at the "Windows flag animation" and never loads anything, I even left it overnight.
And I'm 100% positive the discs are correctly burned (burned them twice in two different pcs) and the isos are not corrupted.

Can you boot either in another Windows 7 PC to see if they can detect an OS to repair after clicking Repair My Computer?

Will they boot correctly if you unplug the HDD?

If the HD tests OK then try resetting the BIOS to defaults: Clear CMOS - 3 Ways to Clear the CMOS - Reset BIOS

Will the WDO bootable AV scan disk boot and run?