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.