The Linux/Win thing has been done to death. I've even contributed on Digg etc. Not a great deal of sense talked about it. In the context of the current political situation there are a few issues to consider which generally aren't covered much related to putting this question in the context of a survivalist situation. Such as...
Whether you can afford Windows Vista or sucessors come the economic collapse
Criminalisation of breach of Copyright (pirate copies of Windows or other software)
Criminalisation of data stewardship - (state ownership and claim on all private data via extension of Data Protection acts etc)
Criminalisation of methods of encryption - (classing them as munitions and thus users as potential "combatants")
The levels of policing or "useful incrimination" which might be achieved from the above by local snoops and "clipboard heroes"
Given all of this it may be worth keeping one's options well and truly open
I watched the BBS documentary and had a strong feeling that whilst looking at what seemed "ancient history" of only 10-20 years ago I was looking also at the future of information exchange.
In some countries even NOW, the only way to get up-to-date information, particularly critical medical information, in an extremist regime is to use dialup BBS access.
If you are considering survival post-apocalypse then you might wanna shortlist your requirements and have a look at what can meet these needs whilst giving minimal "leg-up" to The Man.
These would probably be...
All apps as freeware or open-source with no patents or copyrights
TCP/IP connectivity either via piggy-backed broadband or dialup
Possible snail-mail "frisbee net" exchange of data via encrypted CDROM/DVDs or (heaven forbid) floppy disks
Web browser - either text mode such as Lynx/Links
Basic text editor
Email package - (there are umpteen of these for everything right back even to Windows 3.x)
128 bit encryption which has "plausible denial" such as TrueCrypt
Freeware or open source operating system such as Linux or FreeDOS
Secure disk-scrubbing/eraser packages (freeware/open source)
Out of date hardware and/or software but which is still well supported such as NT 4.0, Win3.11, Win32s
I'd steer away from online apps and keep to minimal uptime, possibly even reverting back to dialup should FEMA run rampant
If it does "hit-the-fan" you can expect posession of pirated sofware to be added to the VERY long list of imprisonable offences so it's worth cleaning up your act right now if you have any.
Minimal interest will be shown by snoops in what they cannot understand or are liable to instantly dismiss without looking further
These include obsolete operating systems or rare/niche market operating systems
Might be an idea to have a sacrificial setup which you can allow The Man to confiscate but which has been kept thoroughly sanitised. No porn (ever), no copied games etc. No personal information, disk free space scrubbed using Gutmann or higher overwrite method.
If you think I'm exaggerating, today I received an email asking for urgent help in the UK due to new state-owned tenancy agreements requiring contracts to be issued with photo ID of all tenants including children, the right to search private homes for "drugs" or other criminal breaches etc. (presumably including anything "useful"). This new contract has been dropped on the tenants with only 5 days consultation to object. It is being done by stealth and by changing contracts one area at a time over a long period to prevent unified and popular opposition. How long before the snoop visitors want to image your hard drive or inspect software licences eh?
Just a few thoughts which may be of use!.