Checking Site against older version of I.E.

I use strict xhtml and validate all of my pages.  But there are different ways to check the pages against other versions of browsers (like the ones I listed above).  After using strict xhtml doctype and validating things are usually close enough.  There are times where  some things are slightly off.  It always helps to see what others are seeing.  I have seen some differences with the ways I use, listed above.  It makes me wonder if one of the methods is wrong.  Like   http://www.ipinfo.info/netrenderer/  renders I.E.  within a linux environment so I wonder if this is right?  Or are there better ways than what I am doing now.

There is no way to see pages exactly as other users have it.

A lot of problems exist:
1) what`s IE/Firefox version, which platform?
2) does user have genuine IE (whatever is version) or some hacked one (like yours from http://tredosoft.com/Multiple_IE) or some buggy clone (like AvantBrowser, Maxthon, MYIE2)?
3) Safari ::beep::!
4) Microsoft`s virtual images can expire.
5) virtual machines slow down your PC performance so you cannot use adobe, core etc in full power.

So my advice is to make enviroment as natural as possible. Work on one PC and test it on other one with different OS`s and browsers installed. Once you have a good result on one browser - save it and try on another. Iterate all.

Moreover when you will be experienced enough you want need all this stuff. Just for final check.

Good luck.

@5) virtual machines slow down your PC performance so you cannot use adobe, core etc in full power.
If you run them with enough memory and full specs, the differences are few. Adobe pdfs were developed to be standardized and cross platform so that should not be an issue. If you only have one machine, the best way to have multiple platforms is with virtual machines. You don't have to run them all at once, it can be one at a time. It is also not a good idea to iterate through browsers and correct your code for each one. It is probably a better idea to follow W3C web standards and practices; you'll find that many of the browser anomalies with disappear when the standards are use. Also, these guidelines will strengthen your ADA compliance since they parallel greatly. Only after these guidelines are followed should design issues be taken into account on an iterative basis.

Microsoft f...  W3C and all standards =)

Safari has become available for windows just recently.

http://www.apple.com/nl/safari/download/

Good luck!