MinGW Portable is supposed to be truly portable. That means you should be able to use it on whatever computer you're running it from without making adjustments. However, after switching computers back and forth, I am having a problem with $HOME directory not found. One computer recognizes my USB flash as E: while another sees it as G:. Now MSYS is looking for $HOME in drive E: when $HOME is supposed to be in drive G:.
Setting the $HOME environment variable in Vista was no use, unlike in Cygwin. After some fiddling, I found a solution. I have to manually modify
/etc/fstab. If my USB flash containing MinGW Portable is on G:, I have to navigate to
fstab in a text editor and change the drive letter. The following is what looks like in
G:/PortableApps/MinGWPortable/App/MinGW /mingw G:/PortableApps/MinGWPortable/Data/home /home