When using 4gig of ram i know 32 wont read all of it... but for a gaming machine will 64 bit have some compatibility issues? especially with older games like quake 3 etc, as i still like playing old games as well as new. would a more sensible bet be 32 bit for the compatibility factor.. knowing that everything will work?

shouldnt have any problems used Quake 3 on vista 64bit with no problems, if you do have any issues make the prog run as administrator

Cool, i just remember people saying that 64 bit has compatibility problems with some games/apps is this just lies?

The older the game is the more chance there might be some issue, with either Vista itself or, and this is less likely, with 64 bit. I'm no expert at determining when or why, the situation seems a little murky to me as to why exactly. By and large 32 bit programs run fine under 64 because the processor actually has a 32 bit alternate mode that it runs 32 bit code inside of. Many older games that don't run in vista will run if you run them 1. as administrator and/or 2. in XP compatibility mode - both options are easily selected by right clicking the exe file and going into 'properties'.

The bottom line is that many of us heavy gamers are using 64 and loving it and everything seem to just work, new games and old - but there may be exceptions, to be sure about an older game you will likely need to research it individually.

Some software will need a 64 bit version to run, not many, but a few, probably because they have a low level, driver type component to them. CD emulators, some security software, are a few examples. So far I found a 64 bit version easily available for all I wanted to run.

That so many enthusiasts and gamers are using 64 ought to tell you that by and large the water is nice.

Basically vista x64 will play most 32-bit games no problem (I've never run into any problems, even played QIII), it's just when you start trying to run dos games, you'll need to pick up an emulator.

If you have 16 bit games/apps, or 32 bit games/apps with a 16 bit installer, then you won't be able to run them. The model for drivers was also changed for Vista, (can't be run in kernel mode any more), so old drivers/devices no longer work. But if you are using components newer than 3 years, there should be no problems.

Unless you buy Creative products. In that case, you would be best advised to continuously launch days old rotting roadkill carcasses at their headquarters. Burning torches and Trebouchet optional, of course. A more modern alternative may be to run around the parking lot on VERY hot days, putting tablespoons of Fish Paste into the air conditioninig intakes of everyone's cars. This is a HIGHLY effective method for letting people know your displeasure.

Well this will be for a new pc next month so the parts will be new.

So 32 bit installers should work with a 64 bit os then?

Correct - Vista 64 runs 32 bit software just fine. As a user, 99% of the time you'll notice no difference between the 32 and 64 bit versions. The differences are that occasionally, you may have to specify a compatibility mode (right click.. Properties...). That Vista 64 has a pathological hatred of unsigned digital certificates, so people who like downloading and running shareware from dubious sources may become frustrated that they aren't able to do that until they log into the superadmin account. And that you have two versions of Internet Explorer (32 and 64 bit).