Very slow editing, playback sluggy even after render ...

Question

I working on a movie, footage is mostly 1080p 50 fr. For the moment the movielenght on the timeline  is only 8 minutes and editing is becoming so hard because of the slowness of some tasks...
I explain:
1) At start up loading this latest project is slow
2) Media asset pannel: thumbnails of footage is loading very slow when you go to another folder
3) Pre-viewing of (a part of) the footage already added to the timeline (expertmode) is sluggy, but sometimes even when pre-rendering with the renderbutton is done (the render markers are correct placed) !
Also a crash op PE sometimes happens (but not so frequent)
Final rendering to a format (dvd, mp4 etc) works well but ofcourse it's difficult to make a good movie if pre-viewing of the timelinefootage is not working well ...
So my question is if I replace my internal (ram) memory in my pc from 8 GB to 16 GB, would this fix all this 3 problems ?
I have only 2 memory banks, now with 2x4 gb so I would have to buy 2x8 that's more than 100 euro (more than PE itselfs thus ...).
My pc works well for a recent game like Far Cry 3 so I don't need the memory for other programs ... So I want to be shure if this will fix it.
Finally, my config: PC has a small ssd with win 7 home premium and PE 11 dutch, all other data on traditional HD, separate ghraphics card:
MEDION® AKOYA® PC P5368 E
bought in dec 2012
CPU-type
Intel Core i7 3770
ram
8GB
Geheugentype
DDR3
motherboardchipset
Intel H61
bus hd
SATA-600
Optische Drive Type
DVD+/-RW DL
Videochip
GeForce GTX 560
Opslagcapaciteit
64GB
Hardeschijftype
Solid State Disk
Opslagcap. tweede schijf
1,5TB
Hardeschijftype tweede schijf
7200rpm

Answer 1

John T Smith wrote:
What is the "normal way" is not what you need to do for Premiere Elements... the program will not ask you for your admin password, it will simply fail
This note is for a different program, but the steps are the same
Run as Administrator http://forums.adobe.com/thread/969395
That's almost the same as right-click and runas admin, the only difference is that you don't have to right-click. The problem with this solution I mentioned above already:
windows acts than like you are the admin and the admin documentsfolderlocations is the standard instead of yours folderlocations (so all your footage, pictures and all data you want to use in your project should be than in the admin documentsfolders instead of your own user folder ....
Than it's better to change the useraccountpermission in admin, that's what I did now. So I'm working with an account with full adminrights now. That's not very safe but I want to give it a try for the time of the project-in-use . I've updated also the graphic and audio drivers.
I've also disabled temporary AV.
All this didn't change anything for loading the thumbnails when you open a project. It still takes minutes to load and the first time after startup opening a subfolder in the assetspanel also takes again minutes (only the first time after startup, if you later go back in that subfolder thumbnails are showed almost directly).
Play-back of timeline seems almost ok now, but this was already yesterday the case (since the scratchlocations didn't change anymore)
In the manual I read that it is advised to defrag the scratchlocations from time to time. But win vista/7/8 have auto defrag ... ?