How much space does Windows 7 take on a SSD?

I'd go as high as possible space wise (in range of your budget, of course). Windows 7 64-bit can "grow" between 15-20GB with the page files, temp files, etc... If you went with a 64GB SSD, you'll be alright with a few other programs on there as well.

My Windows 7 system uses 53GB. It has no pagefile, but it does have a 10GB hibernate file. I have Microsoft Office 2007, Visio, and Visual Studio 2008, Adobe Web Premium CS4 (includes Photoshop, Dreamweaver, Acrobat, Flash, etc.), as well as a couple of dozen other smaller apps. No games. For that amount of space I'd consider 80GB to be the minimum.

40GB will probably be OK. But if you use some heavy programs like 3d modeling you will get it strart faster if you install them on SSD. So 80GB seems to be preferred.

Trust me, dont get less then 80G, or forget about it. Windows will take 20+ and that will allow you like 1 good game if its on a dual layer dvd.

I have a 80G intel ,and I got 8G left after installing ofice 2010, WoW, some anti virus, and a few other small apps, and Adobe CS4 suite.

Check into one of the new Hybrid drives if your budget is under $200

http://www.newegg.com/Product/Product.aspx?Item=N82E168...

I also intended to buy a cheap SSD for my win7 installation and then use a large capacity conventional HD for all of my other applications/file storage, the reason being that I want to make my media center boot as fast as possible from cold.

my question would be how can I make sure my win7 installation is as clean as possible and that all additional information that installs in association with the operating system goes to the ssd and not the HD.

my guess is that this would largely happen automatically but if anyone with greater technical experience could advise on particular problems that would make this approach problematic I would like to know.

At the moment this seems to me to be the most economic way to make use of ssd drives I am also aware of hybrid drives but I don't see them as a long term solution.

ultimately ssd may emerge as a cost effective storage solution but right now its just not competitive with conventional HD's...

I have Windows 7 Pro 64bit installed on my ssd. I did a clean install and did the space saving tweaks 2 months ago. Windows currently uses just a little bit over 21GB on my pc. A 60GB ssd is more than sufficent for Windows 7 and a few software applications. My grand total with software applications and utilities is 36GB used. As you can see sminlal wound up with a total of 53GB. How much capacity is required depends on what software is going to be installed. If you install games on a ssd, then the space used will increase rapidly.

Do you use your hibernate option? I've turned mine off as I never use it and I couldn't afford to have 10 Gb consumed for nothing!!    

Mine - 33 Gigs. No Hibernation, Page file limited to 1 gig and set to a 2nd SSD data drive.
NO games, Office, paintshop, blu-ra,aayby half a dozen other soft ware apps loaded.

Me - Min siz 64/80 gig, recommended 90->128 Gig.

I know you guys were trying to help, but you neglected a better solution that fits easily in his budget. Buy an SRT enabled MOBO and SSD package to replace that old motherboard. A tiny 20GB SSD would plug into the mSATA port next to the CPU on the mobo, and would retain a copy of only the most frequently used programs. (Copying all of windows to a SSD is rather a waste since you only use a fraction of it). He can get a MOBO for under 100 bucks and the SSD for less than 50, that puts him in well under budget while he keeps everything else from his previous system. Even if his previous processor is incapable, he can get a dual core pentium for under 80 bucks - still in his range and with a TREMENDOUS boost in speed for the overall system (with less power usage required due to the new system specs).

Cooler, more stable, faster than just adding a 500gig SSD to his existing system, what's not to love>? (Any idiot has to realise that the new SATAIII he would get on the mSATA mobo would rock his world.)

I have a 120gb OCZ Sata 3 and Windows 7 Ultimate and windows alone is taking 39.6   wish it didn't hope this helps and for a 120gb SSD you are looking at about 150 maybe a little less if you can shop around or catch a special and a 90gb is about 100 to 120 dollars wouldnt suggest less because World of Warcraft is a little less tehn 30 gb or about 10gb or less for Battlefield 3 and of course whatever your various non gaming apps run you soak up the HDD space so I would definitly get 90 or more gig's, Happy Hunting

Im hunting for this answer for both WINXP Pro SP3 and WIN7 Pro 64-bit also. i found out exactly what the OS takes for ea. The resonses here gave food for thought as well. Flash drives just began announcing sales for 64 GB USB drives. Thats another topic too if you want to boot off of them...now you can! I want to throuw our one pc of info too. Consider that the OS takes an approx amt of memory but also figure in amts of progs you will install: A/V, WP Suite, a game or two (you can install one at a time and then uninstall when not playing), some shareware like HULU, Pandora, etc. Take out your calc and tally it all up. Thats what you need for an SSD. Good sales now too on newegg.com and amazon.com as usual. Just saw a 128 GB SSD for a great price yesterday on the Egg. Most applications want to pin themselves to the drive the OS resides on so that will be all of the utils & games you have in addition to the OS. You can use a reg HD, USB drive or even flash media externally off a USB reader for storing anything else. As long as the progs dwell on the drive the OS lives on to open them up. I sometimes had funky exps when installing my RPG games on a drive i used just for storage. I always have 3-4 1TB WD drives in my case for storage. Some of my games can run 80GB! ea. I never install more than 2 at a time and i have quite the selection. Hope this hlps...w/sales now, you can afford the 128GB SSD going for $90 or so...

I'm building a system and will be having a dedicated 128Gb Adata SSD drive just for Win 7 64 bit. I will use a hard drive for programs. 128Gb may seem overkill just for an OS but better to have more than tinkering on the 'just about have enough space' situation.

You never know with the size of Windows updates. Try and factor that into your quest for an SSD.

Kind regards

Almost 60 days Win 7 64bit over Transcend 128 Gb SSD - under 50 % full
MS Office
And bunch of apps i use - HD playback , Encoding , Games, Movies
Games, Movies -> goes to 2-d HDD SATA3 500Gb Standart drive ( or may be 2x HDD over RAID 0 )
Adv. - you can Move you profile folders to 2-d HDD drive - Downloads even MyDokuments etc.

If you have Desktop + SSD go for 64Gb min and 128 Gb is recommended by me
Kill hybernate - Ctrl. + R - > powercfg /hibernate off
Go for 8Gb DDR3 min. and kill page file - set page to ZERO
4 Channel Memmory with 16Gb DDR3 - recomendet by me
Grab what ever SSD XXX Gb you like and forget about R/W Mbps or IO FLOPS - even cheaper one is 100x Random R/W better than Standart HDD - typical 100 μs and standart HDD is 10 - 12 ms

I can still have 50 % for some games on SSD - loading time is MIND-BLOWER  

I read above solution - mSATA running just some portion of OS over mSATA is not something i personally prefer rather OS over SSD.

There you can see my passmark :
I`m waiting ATI 8870 to show up  
PassMark - SSD