I downloaded wubi a couple of months ago and realised it made my laptop bootup significantly slower. It has also made it slower in general.
Recently I have been trying to uninstall wubi from my laptop but I cant. This is because I cannot find any of the wubi or ubuntu files. This is hard because I cant unistall it and I don't know where to search for the files.
The WubiGuide shows how to uninstall Wubi both automatically and manually.
Installing Wubi is not likely to have any effect on your computer speed (in Windows) unless you are very low on space. The main part of a Wubi install is the virtual disk which is the file \ubuntu\disks\root.disk (on the 'drive'/partition you installed to). By removing this and other Wubi files (through the normal uninstall process, or manually if required) this will free up the space and restore your computer back to the original state prior to install.
I recommend running chkdsk and defragmenting your Windows drive as well. After this is done, you can make sure that you have recovered the space. In rare cases the root.disk may be corrupted and recovered by Windows to a hidden \found.000 folder. After running chkdsk you can check for these and remove them if you don't think the space has been fully recovered. Note: the \found.000 folder is hidden and protected by Windows.
You mean you install Ubuntu in Window partition using Wubi? it that, you can remove the Ubuntu like a application in Window control panel easily. I strongly suggest you install ubuntu on a independent partition on your hard disk and use grub to load dual OS.
I don't think Wubi would affect bootup speed.
To remove WUBI I would remove C:\ubuntu and C:\wubildr* and the remove the boot.ini entry and the deleting the registry key: HKLM\Software\Microsoft\Windows\CurrentVersion\Uninstall\Wubi
edits: added full procedure to remove wubi.
