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1. CTRL+ALT+TAB shows the switcher, but you don't have to hold the keys. You can then cycle through with TAB/SHIFT+TAB, or the arrow keys. Aero Peek is the feature that hides everything else temporarily and shows you the actual window, which you can disable from the Taskbar configuration settings I think.
2. Using registry key (included below) as answered elsewhere

Windows Registry Editor Version 5.00

; Customize Alt+Tab settings, like Alt+Tab Tuner
; http://cybernetnews.com/cybernotes-bigger-thumbnails-for-vistas-alt-tab/

[HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\AltTab]
"BottomMarginPx"=dword:0000000a
"MaxIconSizePx"=dword:0000015e
"MaxThumbSizePx"=dword:0000012c
    ; sizing:
    ;   1024×768: MaxThumbSizePx = 00000078
    ;   1280×1024: MaxThumbSizePx = 0000009E
    ;   1680×1050: MaxThumbSizePx = 000000d2 (=210)
    ;   1920×1200: MaxThumbSizePx = 000000f5 (=245)
"MinThumbSizePcent"=dword:00000064
    ; ^ 100
"MinWidthPx"=dword:0000012c
"OverlayIconDXPx"=dword:00000000
"OverlayIconDYPx"=dword:00000000
"OverlayIconPx"=dword:00000030
"SideMarginPx"=dword:00000014
"TextBottomPx"=dword:000001f4
"ThumbSpacingXPx"=dword:00000014
"ThumbSpacingYPx"=dword:00000014
"TopMarginPx"=dword:0000003c
    ; the following require force-quit explorer:
    ;   ctrl+shift+right click in start menu >> Exit Explorer
    ;   ctrl+shift+esc to open task manager >> File >> Run >> explorer.exe
    ; see Daniel Martin's second reply http://social.technet.microsoft.com/Forums/en/w7itproui/thread/9ebf508d-835f-4603-9dea-5b6bfdeda93e
"Columns"=dword:00000005
"Rows"=dword:00000005


; additional column configuration tip via http://superuser.com/a/56129
;   requires restart
; source http://technet.microsoft.com/en-us/library/cc784579%28WS.10%29.aspx
; source 2: http://exodusdev.com/content/revert-xp-style-alt-tab-coolswitch-behavior-windows-7-and-windows-vista#comment-656
; note: if there are more icons than would be available for Columns x Rows, it should scroll the extras
; NOTE: this only affects the classic style of XP switching
[HKEY_CURRENT_USER\Control Panel\Desktop]
"CoolSwitchColumns"="5"
"CoolSwitchRows"="5"


; ; disable Vista-style previews, use XP-style icons only -- http://superuser.com/a/114058/135416
; ; can also access via LEFT_ALT+RIGHT_ALT (release)+TAB -- http://superuser.com/a/114047/135416
; [HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer]
; "AltTabSettings"=dword:00000001

1. CTRL+ALT+TAB shows the switcher, but you don't have to hold the keys. You can then cycle through with TAB/SHIFT+TAB, or the arrow keys. Aero Peek is the feature that hides everything else temporarily and shows you the actual window, which you can disable from the Taskbar configuration settings I think.
2. Using registry key (included below) as answered elsewhere

Windows Registry Editor Version 5.00

; Customize Alt+Tab settings, like Alt+Tab Tuner
; http://cybernetnews.com/cybernotes-bigger-thumbnails-for-vistas-alt-tab/

[HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\AltTab]
"BottomMarginPx"=dword:0000000a
"MaxIconSizePx"=dword:0000015e
"MaxThumbSizePx"=dword:0000012c
    ; sizing:
    ;   1024×768: MaxThumbSizePx = 00000078
    ;   1280×1024: MaxThumbSizePx = 0000009E
    ;   1680×1050: MaxThumbSizePx = 000000d2 (=210)
    ;   1920×1200: MaxThumbSizePx = 000000f5 (=245)
"MinThumbSizePcent"=dword:00000064
    ; ^ 100
"MinWidthPx"=dword:0000012c
"OverlayIconDXPx"=dword:00000000
"OverlayIconDYPx"=dword:00000000
"OverlayIconPx"=dword:00000030
"SideMarginPx"=dword:00000014
"TextBottomPx"=dword:000001f4
"ThumbSpacingXPx"=dword:00000014
"ThumbSpacingYPx"=dword:00000014
"TopMarginPx"=dword:0000003c
    ; the following require force-quit explorer:
    ;   ctrl+shift+right click in start menu >> Exit Explorer
    ;   ctrl+shift+esc to open task manager >> File >> Run >> explorer.exe
    ; see Daniel Martin's second reply http://social.technet.microsoft.com/Forums/en/w7itproui/thread/9ebf508d-835f-4603-9dea-5b6bfdeda93e
"Columns"=dword:00000005
"Rows"=dword:00000005


; additional column configuration tip via https://superuser.com/a/56129
;   requires restart
; source http://technet.microsoft.com/en-us/library/cc784579%28WS.10%29.aspx
; source 2: http://exodusdev.com/content/revert-xp-style-alt-tab-coolswitch-behavior-windows-7-and-windows-vista#comment-656
; note: if there are more icons than would be available for Columns x Rows, it should scroll the extras
; NOTE: this only affects the classic style of XP switching
[HKEY_CURRENT_USER\Control Panel\Desktop]
"CoolSwitchColumns"="5"
"CoolSwitchRows"="5"


; ; disable Vista-style previews, use XP-style icons only -- https://superuser.com/a/114058/135416
; ; can also access via LEFT_ALT+RIGHT_ALT (release)+TAB -- https://superuser.com/a/114047/135416
; [HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer]
; "AltTabSettings"=dword:00000001

Windows Registry Editor Version 5.00

; Customize Alt+Tab settings, like Alt+Tab Tuner
; http://cybernetnews.com/cybernotes-bigger-thumbnails-for-vistas-alt-tab/

[HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\AltTab]
"BottomMarginPx"=dword:0000000a
"MaxIconSizePx"=dword:0000015e
"MaxThumbSizePx"=dword:0000012c
    ; sizing:
    ;   1024×768: MaxThumbSizePx = 00000078
    ;   1280×1024: MaxThumbSizePx = 0000009E
    ;   1680×1050: MaxThumbSizePx = 000000d2 (=210)
    ;   1920×1200: MaxThumbSizePx = 000000f5 (=245)
"MinThumbSizePcent"=dword:00000064
    ; ^ 100
"MinWidthPx"=dword:0000012c
"OverlayIconDXPx"=dword:00000000
"OverlayIconDYPx"=dword:00000000
"OverlayIconPx"=dword:00000030
"SideMarginPx"=dword:00000014
"TextBottomPx"=dword:000001f4
"ThumbSpacingXPx"=dword:00000014
"ThumbSpacingYPx"=dword:00000014
"TopMarginPx"=dword:0000003c


; additional column configuration tip via http://superuser.com/a/56129
;   requires restart
; source http://technet.microsoft.com/en-us/library/cc784579%28WS.10%29.aspx
; source 2: http://exodusdev.com/content/revert-xp-style-alt-tab-coolswitch-behavior-windows-7-and-windows-vista#comment-656
; note: if there are more icons than would be available for Columns x Rows, it should scroll the extras
[HKEY_CURRENT_USER\Control Panel\Desktop]
"CoolSwitchColumns"="5"
"CoolSwitchRows"="5"


; ; disable Vista-style previews, use XP-style icons only -- http://superuser.com/a/114058/135416
; ; can also access via LEFT_ALT+RIGHT_ALT (release)+TAB -- http://superuser.com/a/114047/135416
; [HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer]
; "AltTabSettings"=dword:00000001

Windows Registry Editor Version 5.00

; Customize Alt+Tab settings, like Alt+Tab Tuner
; http://cybernetnews.com/cybernotes-bigger-thumbnails-for-vistas-alt-tab/

[HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\AltTab]
"BottomMarginPx"=dword:0000000a
"MaxIconSizePx"=dword:0000015e
"MaxThumbSizePx"=dword:0000012c
    ; sizing:
    ;   1024×768: MaxThumbSizePx = 00000078
    ;   1280×1024: MaxThumbSizePx = 0000009E
    ;   1680×1050: MaxThumbSizePx = 000000d2 (=210)
    ;   1920×1200: MaxThumbSizePx = 000000f5 (=245)
"MinThumbSizePcent"=dword:00000064
    ; ^ 100
"MinWidthPx"=dword:0000012c
"OverlayIconDXPx"=dword:00000000
"OverlayIconDYPx"=dword:00000000
"OverlayIconPx"=dword:00000030
"SideMarginPx"=dword:00000014
"TextBottomPx"=dword:000001f4
"ThumbSpacingXPx"=dword:00000014
"ThumbSpacingYPx"=dword:00000014
"TopMarginPx"=dword:0000003c
    ; the following require force-quit explorer:
    ;   ctrl+shift+right click in start menu >> Exit Explorer
    ;   ctrl+shift+esc to open task manager >> File >> Run >> explorer.exe
    ; see Daniel Martin's second reply http://social.technet.microsoft.com/Forums/en/w7itproui/thread/9ebf508d-835f-4603-9dea-5b6bfdeda93e
"Columns"=dword:00000005
"Rows"=dword:00000005


; additional column configuration tip via http://superuser.com/a/56129
;   requires restart
; source http://technet.microsoft.com/en-us/library/cc784579%28WS.10%29.aspx
; source 2: http://exodusdev.com/content/revert-xp-style-alt-tab-coolswitch-behavior-windows-7-and-windows-vista#comment-656
; note: if there are more icons than would be available for Columns x Rows, it should scroll the extras
; NOTE: this only affects the classic style of XP switching
[HKEY_CURRENT_USER\Control Panel\Desktop]
"CoolSwitchColumns"="5"
"CoolSwitchRows"="5"


; ; disable Vista-style previews, use XP-style icons only -- http://superuser.com/a/114058/135416
; ; can also access via LEFT_ALT+RIGHT_ALT (release)+TAB -- http://superuser.com/a/114047/135416
; [HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer]
; "AltTabSettings"=dword:00000001

Update Corrected my row/column misconceptions -- most of my sources were wrong until I stumbled across the correct explanation.

I know this is old, but

1. CTRL+ALT+TAB shows the switcher, but you don't have to hold the keys. You can then cycle through with TAB/SHIFT+TAB, or the arrow keys. Aero Peek is the feature that hides everything else temporarily and shows you the actual window, which you can disable from the Taskbar configuration settings I think.
2. Using registry key (included below) as answered elsewhere

Here are some registry settings to customize ALT+TAB behavior - I'm combining several sources (indicated in comments). Note I've made the preview thumbnail size much larger; without restarting your computer the columns setting won't take effect, and so if your resolution is too small this will push some thumbnails off the screen. I've included the registry key for #2, but disabled since that would defeat the purpose of the other customizations.

Windows Registry Editor Version 5.00

; Customize Alt+Tab settings, like Alt+Tab Tuner
; http://cybernetnews.com/cybernotes-bigger-thumbnails-for-vistas-alt-tab/

[HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\AltTab]
"BottomMarginPx"=dword:0000000a
"MaxIconSizePx"=dword:0000015e
"MaxThumbSizePx"=dword:0000012c
    ; sizing:
    ;   1024×768: MaxThumbSizePx = 00000078
    ;   1280×1024: MaxThumbSizePx = 0000009E
    ;   1680×1050: MaxThumbSizePx = 000000d2 (=210)
    ;   1920×1200: MaxThumbSizePx = 000000f5 (=245)
"MinThumbSizePcent"=dword:00000064
    ; ^ 100
"MinWidthPx"=dword:0000012c
"OverlayIconDXPx"=dword:00000000
"OverlayIconDYPx"=dword:00000000
"OverlayIconPx"=dword:00000030
"SideMarginPx"=dword:00000014
"TextBottomPx"=dword:000001f4
"ThumbSpacingXPx"=dword:00000014
"ThumbSpacingYPx"=dword:00000014
"TopMarginPx"=dword:0000003c


; additional column configuration tip via http://superuser.com/a/56129
;   requires restart
; source http://technet.microsoft.com/en-us/library/cc784579%28WS.10%29.aspx
; source 2: http://exodusdev.com/content/revert-xp-style-alt-tab-coolswitch-behavior-windows-7-and-windows-vista#comment-656
; HKCU\Control Panel\Desktop
[HKEY_CURRENT_USER\Control Panel\Desktop\CoolSwitchColumns]
@="5"

; note: if there are more icons than would be available for Columns x Rows, it should scroll the extras
[HKEY_CURRENT_USER\Control Panel\Desktop\CoolSwitchRows]
@="5"


; ; disable Vista-style previews, use XP-style icons only -- http://superuser.com/a/114058/135416
; ; can also access via LEFT_ALT+RIGHT_ALT (release)+TAB -- http://superuser.com/a/114047/135416
; [HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer]
; "AltTabSettings"=dword:00000001

I know this is old, but

1. CTRL+ALT+TAB shows the switcher, but you don't have to hold the keys. You can then cycle through with TAB/SHIFT+TAB, or the arrow keys. Aero Peek is the feature that hides everything else temporarily and shows you the actual window, which you can disable from the Taskbar configuration settings I think.
2. Using registry key (included below) as answered elsewhere

Here are some registry settings to customize ALT+TAB behavior - I'm combining several sources (indicated in comments). Note I've made the preview thumbnail size much larger; without restarting your computer the columns setting won't take effect, and so if your resolution is too small this will push some thumbnails off the screen. I've included the registry key for #2, but disabled since that would defeat the purpose of the other customizations.

Windows Registry Editor Version 5.00

; Customize Alt+Tab settings, like Alt+Tab Tuner
; http://cybernetnews.com/cybernotes-bigger-thumbnails-for-vistas-alt-tab/

[HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\AltTab]
"BottomMarginPx"=dword:0000000a
"MaxIconSizePx"=dword:0000015e
"MaxThumbSizePx"=dword:0000012c
    ; sizing:
    ;   1024×768: MaxThumbSizePx = 00000078
    ;   1280×1024: MaxThumbSizePx = 0000009E
    ;   1680×1050: MaxThumbSizePx = 000000d2 (=210)
    ;   1920×1200: MaxThumbSizePx = 000000f5 (=245)
"MinThumbSizePcent"=dword:00000064
    ; ^ 100
"MinWidthPx"=dword:0000012c
"OverlayIconDXPx"=dword:00000000
"OverlayIconDYPx"=dword:00000000
"OverlayIconPx"=dword:00000030
"SideMarginPx"=dword:00000014
"TextBottomPx"=dword:000001f4
"ThumbSpacingXPx"=dword:00000014
"ThumbSpacingYPx"=dword:00000014
"TopMarginPx"=dword:0000003c


; additional column configuration tip via http://superuser.com/a/56129
;   requires restart
; source http://technet.microsoft.com/en-us/library/cc784579%28WS.10%29.aspx
; source 2: http://exodusdev.com/content/revert-xp-style-alt-tab-coolswitch-behavior-windows-7-and-windows-vista#comment-656
; note: if there are more icons than would be available for Columns x Rows, it should scroll the extras
[HKEY_CURRENT_USER\Control Panel\Desktop]
"CoolSwitchColumns"="5"
"CoolSwitchRows"="5"


; ; disable Vista-style previews, use XP-style icons only -- http://superuser.com/a/114058/135416
; ; can also access via LEFT_ALT+RIGHT_ALT (release)+TAB -- http://superuser.com/a/114047/135416
; [HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer]
; "AltTabSettings"=dword:00000001