startup repair loop - only boots into debugging mode

acer aspire, win7 home premium x64. it froze while using VLC (i had not downloaded or installed anything new), shut down, flashed a BSOD kernel error, then started an infinite startup repair loop. i have tried advanced boot options; all of them just begin running startup repair (which runs for hours and then hangs before it completes) except for debugging mode, which boots up just fine.

running a chkdsk now from the debug mode. previously i had put my HDD into an external so that i could run it through another comp and figure out if it was a hardware failure. the drive showed no filing system, so i ran recuva and backed up all the data. ran chkdsk /f and it repaired a couple bad sectors. then the drive opened normally, no errors. ran chkdsk R/ to be sure, but it hung on stage 4 for 8 hrs so i ended the process.

after replacing the hdd into the aspire and figuring out that i can boot into debugging mode, i'm re-running the chkdsk. it seems to have frozen again. is this an indication that the HDD is failing? should i just replace it and re-install win7?

hi,

unfortunately i can't boot into the system recovery because it asks for an administrator password, and i have none nor did i ever set up a password. i can't bypass by leaving it blank or hitting enter.

Turns out I could boot in debugging mode. From there I ran a virus scan, found some nasties, deleted them and my laptop booted up again normally.