I recently bought a new pc with Vista already loaded, with a voucher for upgrading to Windows 7. When applying for the upgrade software a bright spark informed me that 32-bit software could not address more than 3GB of memory, and as the pc had 4GB it must be the 64-bit version of the software. When I received the 'upgrade' CD it was a Recovery Disc, 64-bit. It will be necessary to perform a clean install to 'upgrade' to W7 - my query is, is there any reason why I should not install the 64-bit version? And what benefits will I derive from 64-bit version, if installed?The currently installed software is Vista Home Premium, updated to 6.0.6002, Pack 2, Build 6002; the pc uses an AMD Phenom 9650 Quad processor, 2.3GHz.

Going from 32 to 64 bit will require a clean install.If you've really been given a recovery disk rather than an upgrade DVD, it'll wipe everything anyway.A 32 bit version supports 4GB of RAM, but not all of it will be available to Windows. I won't hunt down the best link to a discourse on the limits of 32 bit Windows, but it boils down to there being a 4GB address space, with some of the addresses being reserved for purposes other than RAM.The main reasons for not installing the 64 bit version involve compaitibility. Most 32 bit application run fine (in emulation) under Win7 X64, but not all. 64 bit drivers are required. 16 bit software won't run at all; I've read that includes 16 bit installers for some 32 bit applications. Unsigned drivers cannot be installed, but that's less of a restriction than you might guess: I've experimented with non-WHQL graphics card drivers. It takes an extra mouse click to give permission to install the drivers, but no extra steps after that. A few utilities from small developers (ATITool, for example) won't easily install due to signing issues.64 bit is required for basic nerd cred, of course.

At 66 years of age, I do not think I am seeking basic (or otherwise) nerd cred, but have noticed over 35 years of working with computers that no matter how much faster and cheaper the technology becomes, the development of software has always expanded to fill the space created. As one who used to write full order processing programs which ran on an 8-bit processor in 4 or 8KB of memory, the current 4GB of memory seems enormous - but that doesn't mean that it will be enough in a few years time. Should I take this opportunity to step up to something which will address more than this level of memory?I have run the Windows 7 upgrade advisor report from my existing 32-bit Vista system in an effort to find out what might be the potential problems in converting to 64-bit W7. The report details many programs which will supposedly be fine, with a few possible problem areas. However, the list is far from exhaustive - there are many programs which simply do not appear on either the compatible or the possible issues lists. One of these is - surprisingly - Microsoft Office (2003). Is there are reason for this?The 'update' discs include a Recovery Disc and a 64-bit driver disc, so I assume the pc supplier (Medion) have provided drivers for all the functionality supplied as original with the 32-bit Vista setup. I will clearly have to perform a clean install, then go about re-installing all the programs and any additional devices/drivers again. Such is life.Apart from being able to address more memory, are there any other benefits to the 64-bit version?

The "nerd cred" bit was mostly intended as a joke.I've read some claims about the wonders of 64 bit, but the main argument for using it is the ability to address more RAM. 64 bit applications can make proper use of that, but they are scarce at the moment.I've been running some X64 version of Win7 on my desktop since the availabilty of the public beta. (It has 12GB of RAM.) I have Photoshop CS4. It includes both 32 and 64 bit versions. The 64 bit version can be set to use lots of RAM, but it cannot use 32 bit filters. (I use NeatImage, so I had to spend a bit more to get its X64 version.) I also have to use the 32 bit version to access my Epson scanner utility.I guess I've bought the line that X64 is the future, but I'm not sure that PCs will be of interest to most people in five or ten years. I know of some young adults who rarely use PCs: their iPhones or equivalents serve all of their needs (email, Web access, etc.).

You may well be right that the pc as we know it today will not have too much of a future, and if addressing more memory is the only advantage of 64-bit, perhaps I would be better off getting an upgrade of my existing 32-bit system - which would at least save me a lot of hassle.Many thanks for your input. BTW, I was not offended by the 'nerd cred' suggestion - at my age I would rather like to be a nerd again!

I have used extensively both Ultimate 32 and Ultimate 64. The fable that win32 can only use 3 gig of ram is just that, a fable. There are MANY means to correct the small limitation that Windows 7 32 defaults to. (I use Win7 Ultimate 32 and I have 5 gig avail - do a google search and it is easy to find the patches. ;) ) As to why I patched U32 instead of going with U64? Simple. About 30% of my software and hardware would NOT work in the U64 OS. An example is my TV Video card worked just fine in the 32 bit, but no amount of begging would make the 32 bit dll's work in 64 bit mode. If I stayed with U64 I would need to buy a new TV in card for my media edition portion. Also my Video Card was SLOWER in 64, as the drivers for it 'worked', but in my online games, I barely got 80fps and the resolution sucked. Of course, again, if I bought new hardware that is U64 compatible, I would not have had this problem. My DriveCrypt software that worked fine in U32, caused the dreaded blue screen of death in U64. So if you use any older software, you take a chance the U64 can even run it properly. Simply put. I'm guessing a LOT of manufactures are making the most common, which is 32 bit software, in updates to work with Win7, and may someday get around to completely re programming new for U64, but for now... I'm sticking with what works and is available today. Yet actually you can quickly reduce the most memory hogging part of Win7, by disabling the 'libraries' which spy on all that you do, and even caches it. Then there is the lame excuse that it speeds things up... when in reality it slows things down drastically, steals cpu and memory, and leaves a record of every file, photo, song, or video you watch all neatly in one place for easy viewing by anyone.

Back in the mid-60's, with the 8-bit processor referred to earlier, we could only directly address a point in a 256-byte 'page'; but by indexing different pages we could theoretically work with up to 64KB of memory. But, apart from the fact that such a large memory capacity was only a pipedream, we could not conceive of writing programs in such an inefficient way to need such gigantic capacity! Indexing the pages required more instructions than working in the fundamental 256-byte page, and was in that way slower.I believe the x86 is basically a 16-bit processor which can address 64KB directly, but can work in 32-bit mode (addressing up to 4GB) or 64-bit mode (16TB?). This may only be an analogy, but perhaps the processor has to execute multiple instructions in these extended modes, and is potentially slower.Being cynical, it seems to me that there has not been a new operating system core from MS since the change from Windows for Workgroups to Win95. Each new release has seen additional facilities, pretty interfaces and so on, but has demanded more and more computer grunt to operate, yet each new release seems to leave the user waiting just as long as he did before!I shall take the implied advice you and bobkn have offered and stick with 32-bit until I hear that there is a better reason than is currently the case to upgrade (if that is the word) to 64-bit. Many thanks to you both.