Freezing and Boot Issues

Hi All,

A bit of background. My pc is dual boot with windows 7 being the boot master, with windows 10 as selectable.

Anyway, windows 7 failed to boot seemingly random, coming up with the press ctrl alt del to reboot. Rebooting brought the same screen up.

Then after powering down (then turning off the plug), and back up it booted to the desktop, all be it slowly, but after a few hours of use the different applications froze, with explorer and all other programs stopped, but the mouse moves.

So i started to boot to windows 10. I made 10 the boot master but it still sometimes has the same booting issue. Sometimes the apps freeze but windows 10 quickly resumes. After 3 different HDD testers found no bad sectors or issues. I tried SFC/CHK-DSK using a windows 7 recovery disc but it couldnt find the file from the disc or the windows 7 HDD. Also tried reseting the MBR and all the other boot settinhs but similar to the SFC it couldnt find the files to do so.

So I read that you could reset then by cloning the partition onto another HDD and using the original as a slave. So I downloaded some clone software but when i loaded the program, it and all the other apps (including explorer) froze again the mouse was moving. When the programs unfroze (after about 5 minutes) the windows 7 HDD had vanished from the program and from the "My PC" section.

Any idea what to do now to either diagnose or repair tue issue?
Thabks in advance

My first guess would have been the hard drive, but it sounds like it may be the ram.

Thanks MrInferno. I will test each RAM stick in each RAM slot, as I remember the original motherboard I had, of the same make and model, had one of the RAM slots die after a while, and the manufacturer replaced it for my current one.

Hopefully it is the sticks. I will come back with my results.

I tested the RAM using the windows memory diagnostic utility from both Windows 7 and 10 and neither gave any issues. Would it be preferable to use a 3rd party program like Memtest?
And yes Thrashzone, I installed Windows 7 to me main HDD (1Tb), then purchased a SSD (120Gb) that I installed a fresh Windows 7 on and then upgraded to 10. is this an issue?

Just to add to this, although my pc booted yesterday, had no issues and was working for a good number of hours (6), today I cannot get into any of the OSs as I either get no media detected, please insert media or disk read error please press ctrl, alt + del to restart, which brings me back to one of the two messages. I will also add that at some points, it is taking up to 30-40 seconds to get passed the initial motherboard screen (where it says press 'del' to go into the settings). Any help please?