Laptop became slow after custom installing windows 7 ultimate

hi I recently have windows 7 home premium and I custom install windows 7 ultimate . After installing and booting
to windows 7 ultimate my laptop became so slow there a black screen after windows logo and pauses for almost 2 minutes and slow on everything. I thought deleting windows.old folder using disk cleanup will help me , but it didn't solved any of my problem my laptop is still slow. What do you think should i do?

Please bare in mind, however that doing a fresh installation of Windows 7 may require a purchase of a new product key.

It's probably the drivers. Make sure you are getting the latest from your laptop's manufacturer site.

thanks for answering in this thread, i reformat and install windows 7 in my laptop and this solves everything . thanks for replying though, you two deserve a rep :)

Thanks. Happy New Year.