Do I have to have a Mac computer to restore my iPad

No, you just need iTunes running on a computer with mac OS or Windows

Download iTunes 12.1.3 for Windows (64-bit)

Hardware:

• PC with a 1GHz Intel or AMD processor with support for SSE2 and 512MB of RAM
• To play Standard Definition video from the iTunes Store, an Intel Pentium D or faster processor, 512MB of RAM, and a DirectX 9.0-compatible video card is required.
• To play 720p HD video or an iTunes LP, a 2.0GHz Intel Core 2 Duo or faster processor, 1GB of RAM, and an Intel GMA X3000, ATI Radeon X1300, or NVIDIA GeForce 6150 or better is required.
• To play 1080p HD video, a 2.4GHz Intel Core 2 Duo or faster processor, 2GB of RAM, and an Intel GMA X4500HD; ATI Radeon HD 2400; Nvidia GeForce 8300 GS or better is required.
• Screen resolution of 1024x768 or greater; 1280x800 or greater is required to play an iTunes LP
• 16-bit sound card and speakers
• Broadband Internet connection to use the iTunes Store
• iTunes-compatible CD or DVD recorder to create audio CDs, MP3 CDs, or back-up CDs or DVDs

Software:

• Windows XP Service Pack 3 or later and 32-bit editions of Windows Vista
• 64-bit editions of Windows Vista require the iTunes 64-bit installer; for more information, visit www.itunes.com/download
• 400MB of available disk space
• Screen reader support requires Window-Eyes 7.2 or later; for information about accessibility in iTunes, visit www.apple.com/accessibility
• iTunes is now a 64-bit application on 64-bit versions of Windows Vista. Some third-party visualizers may no longer be compatible with this version of iTunes. Please contact the developer for an updated visualizer that is compatible with iTunes 12.1 or later
• iTunes in the Cloud, iTunes Match, and iTunes Radio availability may vary by country

Download and install it:

iTunes - Apple