RAM preview playing in Real-time but the Video Playback is slow

Hi so I've been using After effects for a couple months now and I have to move to a different laptop that only supports Windows 7 and its CPU is decent and it has 16gb RAM.

I'm using After Effects CC 2017 currently and when I RAM preview the video it plays at half the speed whereas in info it's playing in realtime but I don't see it playing in realtime. The audio is playing in realtime but it's repeating every 3-4 seconds and I'm guessing it's because of the slow video playback. Yes the composition framerate and the preview framerate are the same. After effects worked for like 1 day and I was able to make a 20 seconds edit out of it but when I restarted the software it stopped working again, I tried all the fixes that made it work the first time and it's just not working now. Earlier I got Display Acceleration disabled so to fix that I switched to Software only and none of them work, the Software only worked for me once as mentioned before but now it doesn't help me anymore.

I've been looking on the internet for hours for the fix I just don't see it. I've tried After effects CS6, CC 2015, CC 2018 and now CC 2017 and each of them had their own unique issues. I'm realy hoping that you guys will be able to help me out, I have clients waiting for me to edit their videos please do something.