Delayed PC Boot up

Hi, here's my problem I've read to through multiple posts on this site, but I'm not getting a solid single answer.

Okay if my PC is off and I boot it up, the Fans and any LEDs (minus the hard drive light) turn on, I can hear the hard drive start. Nothing changes on my screen, but the screen saying it's not connect or whatever. Anyways, I hear the Hard drive clicks like it's try to start, usually does about 3 or 4 clicks then it'll just sit there powered on. If I leave it alone for about 20 minutes it will finally boot up to the BIOS boot screen and run through all the stuff eventually coming to my Windows login. If I push my restart/reset button or restart from the start menu it reboots just fine.
Same issues with putting my pc in sleep/stand-by mode it will take forever to actually shut off. When I move the mouse or hit a key to start it back up will acts like it does after it's actually been shut off.
From what I've gathered I think it can only be one of two things either an issue with my power supply, which could be likely, I'm using a 2x 4-pin to 6-pin adapter for my video card. and just about all of the other connections are being used.
OR it could be a RAM issue, I've got 2x 2GB RAM sticks and only have two RAM Slots I've tried swapping them out, using only one at a time and trying it in different slots. I've tried using an eraser on the RAM contacts or whatever they're called. Made sure to use compressed air to clear out the slot before I put the RAM back in.
Just I'd ask here before I bought a new set of RAM or Power supply.

Any specific system spec or hardware brands needed just ask.