I have Windows 7 64 Bit installed on my main PC (specs listed) and have no issues at all with memory useage.. though it does seem to use a little more then the 32 bit version it still doesn't go over 33% on idle on my rig.. Though that could go down more when I get 2 more gigs of ram on Monday.. I'll report back at that time if there's any difference..
running windows 7 on a 64bit needs at least 2gb to run smoothly my daughter had the same problem she had a acer aspire 64bit with 1gb installed..
installed windows 7 and it would make a loud noise all the time and freeze up as well..
just popped in another 1gb and it is so quiet i cant believe the diffrence it makes....
also check that all your programs are 64bit and not 32
Well I know I use a lot but, it's all explainable. Here's how. I idle at 36.6 used or 1,533.976 on a 4 gig. system. Of that number over 700 meg's is used by shared video. And the rest is background tasks and the operating system itself. It was more when using Vista. Shared video can be a bummer in a lot of ways but, I really don't mind it that much.
I'm 690 MB used with my 3 GB Acer Aspire 4732Z ..
Running Windows7 Ultimate X64 SP 1 ..
If you don't like the usage windows 7 used ..
just disabled some services in services.msc ..
Such as Offline Files, Telephony, Windows Search ..
Note that Windows Search using >100 MB Memory usage for Indexing ..