Pdf Won't Let Me Highlight; Any Solutions, Software Or Otherwise?

Ordinarily I like to use the highlight feature on a PDF to mark the important parts in yellow. I have downloaded a PDF that for whatever reason is made resistant to this kind of personal marking. What exactly is the nature of this PDF "protection"?

The PDF I have in mind is a history essay, and all I want to do is highlight it for my personal use. I have tried to highlight it with Foxit, PDF X-Change Viewer, and PDF X-Change Editor. I have tried three times to bring up the PDF with Nitro, and all I get is "Not responding."

I suppose I could convert to another format and maybe that resistance would be gone when I converted back to PDF. But I'd like to know first if there is something I could do directly to the PDF in view without having to convert.



Computer: DELL Dimension 2400
CPU: Intel Pentium 4-2667 (Northwood, D1)
2666 MHz (20.00x133.3) @ 2658 MHz (20.00x132.9)
Motherboard: DELL 0G1548
Chipset: Intel 845GEV (Brookdale-GEV) + ICH4
Memory: 2048 MBytes @ 166 MHz, 2.5-3-3-7
- 1024 MB PC3200 DDR-SDRAM - Kingston K
- 1024 MB PC3200 DDR-SDRAM - Kingston K
Graphics: Intel 82845G/GL/GV Graphics Controller [DELL]
Intel i845G(L) Integrated, 64 MB
Drive: WL120GPA872, 117.2 GB, E-IDE (ATA-7)
Drive: WDC WD2500JB-57GVC0, 244.2 GB, E-IDE (ATA-6)
Drive: HGST HTS545050A7E380, 488.4 GB, Serial ATA 3Gb/s <-> USB
Drive: SAMSUNG CD-R/RW SW-252S, CD-R Writer
Sound: Intel 82801DB(M) ICH4(-M) - AC'97 Audio Controller [A-1]
Sound: Creative Technology SB Live! Series Audio Processor
Network: RealTek Semiconductor RTL8139 PCI Fast Ethernet NIC [A/B/C]
Network: Broadcom 4401 10/100 Integrated Controller
OS: Microsoft Windows XP Home Edition Build 2600
Antivirus: Panda Antivirus Pro 17.0.1
Firewall: Panda Antivirus Pro 17.0.1
Ad Blocker: Adguard, Ad Muncher, Adblock Plus
Default Browser: Maxthon 4.4.8.1000

 

It's possible that the document is an image in a PDF wrapper.
Open the file in PDF-XChange Viewer. Click Document > OCR Pages... and wait for the process to complete.
You should be able highlight text. Remember to select the Text Tool.

 

It worked. Thank you!

 

You're welcome.