For Adobe user… yeah photoshop & illustrator, if you’re using the latest version, I mean Adobe Photoshop CS/CS2 (Version 8/9)… not the very latest CS3 (I’m not sure bout CS3 though). You might wonder why Adobe refuse to give you thumbnails preview for .psd files in explorer windows just like previous version 7… this makes you ain’t easy to view/search for specific files without execute photoshop everytime to preview (or rite klik and view with adobe reader 1 by 1)… some people said just becoz Adobe already provides their own browser inside it, Adobe Bridge or what so ever (I never use it).. and Adobe itself (if I’m not mistaken where I read it before) they said becoz some photoshop files (huge in MBytes) are too complex to preview and may effect your system performance… sometime the thumbnails image are damage (this happen for huge file size) but the files not effected…Some of us are just enough with Irfanview, some just use ACDSee and etc, as image viewer that support .psd. What ever it is I still prefer thumbnails preview for PSD files in explorer windows rather than ‘rite klik & view with’ command… Afterall you can just scroll through within your explorer like you ever wanted… simply download PSD Thumbnails Explorer.rar and extract… follow the Read Me file inside. Then the PSD files will be appear in thumbnails view within explorer.
For Illustrator – to preview thumbnails for .ai in windows see this link.