Windows Movie Maker Video Problems, Please Help!

I've been using WMM since '05 (and 2 years on my current laptop) and never had problems with it. Now, before a week ago everything was still fine, the video clips in the preview screen and timeline were working perfect. BUT...last week when i published a video, only the audio was playing, and i didn't see video. However, prior to the "blackout" WMM put on me, i've had previously published segments from WMM. And not only from that program, but also from Cyberlink Power Director, which came with my computer (i will detail tech specs soon). I imported a few segments from there cause it had some special video effects that WMM didn't have. Now, when i publish the segments that were published before, the video works cause they were already done before the "blackout" happened. But only when i publish new clips does it happen. 

I'm not sure what's going on, i've NEVER had this problem with WMM before, just happened a week ago. I've been scouring around online looking for answers. I doubt it's the codecs or compatibilty tabs. Cause i have tried those...no affect. I have updated my drivers...no affect. And i even restored all defaults...STILL no affect. I'm tempted to uninstall it and re-install it to see if that works, but that's the last resort. If that's what it takes so be it, i would have to start over and re-import the media files. So i need to know, based on my tech specs i'm gonna list below, what's the problem, and how to fix it. I want to continue making and editing videos again, but i can't if this isn't resolved. Thank you so much and i hope to get some answers soon. And not only for me, but others who have the same problems and tech specs as me. God bless!

Tech Specs (if you need more tech specs, please let me know) :

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*2010 model Compaq Presario CQ56 Laptop (purchased brand new in mid-2011, so it's 2 years old)

*Windows 7 Home Premium 64-bit 

*Intel Celeron processor

*Mobile Intel(R) 4 Series Express Chipset Family

Movie Editors i'm using:

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*Windows Movie Maker 6.0- Vista version, which i downloaded

*Windows Live Movie Maker- Came with the laptop

*Cyberlink Power Director- also came with the laptop, but like to use it for the extra features that WMM don't have yet)